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Intersection Safety Issue Briefs

Issue Brief 8

Toolbox of Countermeasures and Their Potential Effectiveness for Intersection Crashes

November 2009
FHWA-SA-10-005

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Introduction

This issue brief documents estimates of the crash reduction that might be expected if a specific countermeasure or group of countermeasures is implemented with respect to intersection crashes. The crash reduction estimates are presented as crash reduction factors (CRFs).

Traffic engineers and other transportation professionals can use the information contained in this issue brief when asking the following types of question: Which countermeasures might be considered at the signalized intersection of Maple and Elm streets, an intersection experiencing a high number of total crashes and left-turn crashes? What change in the number of total crashes and left-turn crashes can be expected with the implementation of the various countermeasures?

Crash Reduction Factors

A CRF is the percentage crash reduction that might be expected after implementing a given countermeasure. In some cases, the CRF is negative (i.e., the implementation of a countermeasure is expected to lead to a percentage increase in crashes).

One CRF estimate is provided for each countermeasure. Where multiple CRF estimates were available from the literature, selection criteria were used to choose which CRFs to include in the issue brief:

Where these criteria could not be met, a CRF may still be provided. In these cases, it is recognized that the reliability of the estimate of the CRF is low, but the estimate is the best available at this time. The CRFs in this issue brief may be periodically updated as new information becomes available.

The Desktop Reference for Countermeasures lists all of the CRFs included in this issue brief and adds many other CRFs available in the literature. A few CRFs found in the literature were not included in the Desktop Reference. These CRFs were considered to have too large a range or too large a standard error to be meaningful, or the original research did not provide sufficient detail for the CRF to be useful.

A CRF should be regarded as a generic estimate of the effectiveness of a countermeasure. The estimate is a useful guide, but it remains necessary to apply engineering judgment and to consider site-specific environmental, traffic volume, traffic mix, geometric, and operational conditions that will affect the safety impact of a countermeasure. The user must ensure that a countermeasure applies to the particular conditions being considered. The reader is also encouraged to obtain and review the original source documents for more detailed information, and to search databases such as the National Transportation Library (http://ntlsearch.bts.gov) for information that becomes available after the publication of this issue brief

Presentation of the Crash Reduction Factors

In the Table presented in this issue brief, the crash reduction estimates are provided in the following format:

CRF(standard error)REF

The CRF is the value selected from the literature.

The use of the color blue and the italicizing of words used in the text (except for words associated with a specific document) are associated with new information provided by the Highway Safety Manual, April 2009 draft, as listed in Reference 43 at the end of this issue brief.

The standard error is given where available. The standard error is the standard deviation of the error in the estimate of the CRF. The true value of the CRF is unknown. The standard error provides a measure of the accuracy of estimate of the true value of the CRF. The August 2008 edition of Issue Brief 5 used the phrase "relatively small" to indicate that a CRF is "relatively accurately known." Relatively small was not explicitly defined several years ago; however, its intention is congruent with the definition used in this edition of the Issue Brief: relatively small is defined as a CRF with a standard error ≤ 10. This is equivalent to the Highway Safety Manual AMFs (Accident Modification Factors) with standard errors of ≤ 0.10.

A "relatively large" standard error associated with a CRF is defined as >10 and indicates that the CRF is "not accurately known."

The standard error may be used to estimate a confidence interval of the true value of the CRF. (An example of a confidence interval calculation is given below.)

The REF is the reference number for the source information.

As an example, the CRF for the countermeasure "provide protected left-turn phase for left-turn fatal/injury crashes" is:

16(6)27

The standard error may be used to estimate a confidence interval of the true value of the CRF. (An example of a confidence interval calculation is given below.)

The following points should be noted:

Using the Tables

The CRFs for intersection crashes are presented in three tables which summarize the available information. The Tables are:

Table 1 Signalization Countermeasures, which includes signal operations countermeasures, signal hardware countermeasures, and combination signal and other countermeasures.

Table 2 Geometric Countermeasures, which includes left turn countermeasures, right turn countermeasures, and other geometric countermeasures.

Table 3 Signs/Markings/Operational Countermeasures, which includes signs, pavement markings modifications, regulatory, lighting, and operational countermeasures Readers familiar with the previous editions of this issue brief will notice the following changes:

The following points should be noted:

Legend

CRF(standard error)REF

CRF is a crash reduction factor, which is an estimate of the percentage reduction that might be expected after implementing a given countermeasure. A number in bold indicates a rigorous study methodology and a small standard error (≤10) in the value of the CRF. Standard error, where available, is the standard deviation of the error in the estimate of the CRF.

REF is the reference number for the source information.

Additional crash types identified in the Other Crashes column:

a: Head-on

b: Run-off-road

c: Overturn

d: Night

e: Day

f: Multiple-vehicle

g: Fixed-object

h: Older-driver

i: Younger-driver

j: Right-turn

k: Speed-related

l: Speed related/day

m: Speed related/night

n: Speed related/dry

o: Speed related/wet

p: Wet

q: Night/wet

r: Pedestrian

s: All turns

t: Bicycle

u: Emergency vehicle

rt. Pedestrian and bicycle

Table 1. Signalization Countermeasures
Countermeasure Crash Severity Control Area Type Configuration All Crashes Left-Turn Crashes Rt-Angle Crashes Rear-end Crashes Sideswipe Crashes Other Crashes Major/ Minor Daily Traffic Volume (veh/day)
Signal Operations Countermeasures
Add all-red clearance interval (from 0 to 1 second) All Signal Urban empty cell empty cell empty cell empty cell empty cell empty cell empty cell empty cell
Add exclusive pedestrian phasing All Signal empty cell empty cell empty cell empty cell 0(44)28 empty cell empty cell r 3416 empty cell
Convert exclusive leading protected to exclusive lagging protected All Signal empty cell empty cell -15(19)15 -49(54)15 empty cell empty cell empty cell empty cell empty cell
Convert permissive or permissive/ protected to protected only left-turn phasing All empty cell empty cell empty cell empty cell 9941 empty cell empty cell empty cell empty cell empty cell
Convert permissive to permissive/ protected left-turn phasingAll All empty cell empty cell empty cell empty cell 1641 empty cell empty cell empty cell empty cell empty cell
Convert protected left-turn phase to protected/ permissive All Signal empty cell empty cell -20(17)15 -65(71)15 empty cell 4(22)15 empty cell empty cell empty cell
Convert protected left-turn phase to protected/ permissive Fatal/ Injury Signal empty cell empty cell -10(25)6 empty cell empty cell empty cell empty cell empty cell empty cell
Convert permissive to protected All Signal Urban 4-leg or 3-leg 6(10)43 99(1)43 empty cell empty cell empty cell empty cell empty cell
Convert permissive to protected/ permissive or permissive/ protected phasing Injury Signal Urban 4-leg empty cell 16(2)43 empty cell empty cell empty cell empty cell 3,000- 77,000/ 10-45,500
Convert permissive to protected/ permissive or permissive/ protected phasing All Signal Urban 4-leg 143 empty cell empty cell empty cell empty cell empty cell empty cell
Convert permissive to protected left-turn phase on multiple approaches All Signal empty cell on 1 approach 643 empty cell empty cell empty cell empty cell empty cell empty cell
Convert permissive to protected left-turn phase on multiple approaches All Signal empty cell on 2 approaches 1143 empty cell empty cell empty cell empty cell empty cell empty cell
Convert permissive to protected left-turn phase on multiple approaches All Signal empty cell on 3 approaches 1743 empty cell empty cell empty cell empty cell empty cell empty cell
Convert permissive to protected left-turn phase on multiple approaches All Signal empty cell on 4 approaches 2243 empty cell empty cell empty cell empty cell empty cell empty cell
Convert permissive to protected/ permissive or permissive/ protected left turn phase on multiple approaches All Signal empty cell on 1 approach 143 empty cell empty cell empty cell empty cell empty cell empty cell
Convert permissive to protected/ permissive or permissive/ protected left turn phase on multiple approaches All Signal empty cell on 2 approaches 243 empty cell empty cell empty cell empty cell empty cell empty cell
Convert permissive to protected/ permissive or permissive/ protected left turn phase on multiple approaches All Signal empty cell on 3 approaches 343 empty cell empty cell empty cell empty cell empty cell empty cell
Convert permissive to protected/ permissive or permissive/ protected left turn phase on multiple approaches All Signal empty cell on 4 approaches 443 empty cell empty cell empty cell empty cell empty cell empty cell
Convert protected/ permissive left-turn phase to permissive/ protected All Signal empty cell empty cell -13(19)17 33(22)17 empty cell empty cell empty cell empty cell empty cell
Improve signal timing [to intervals specified by the ITE Determining Vehicle Change Intervals: A Proposed Recommended Practice (1985)] All Signal empty cell 4-leg 8(9)30 empty cell 4(18)30 -12(16)30 empty cell h 4225 empty cell
Improve signal timing [to intervals specified by the ITE Determining Vehicle Change Intervals: A Proposed Recommended Practice (1985)] All Signal All empty cell empty cell empty cell empty cell empty cell empty cell f 511 empty cell
Improve signal timing [to intervals specified by the ITE Determining Vehicle Change Intervals: A Proposed Recommended Practice (1985)] All Signal empty cell empty cell empty cell 759 empty cell empty cell empty cell empty cell empty cell
Improve signal timing [to intervals specified by the ITE Determining Vehicle Change Intervals: A Proposed Recommended Practice (1985)] Fatal/ Injury Signal empty cell empty cell empty cell 559 309 empty cell empty cell a 759 empty cell
Improve signal timing [to intervals specified by the ITE Determining Vehicle Change Intervals: A Proposed Recommended Practice (1985)] Fatal/ Injury Signal empty cell empty cell empty cell empty cell empty cell empty cell empty cell b 629 empty cell
Improve signal timing [to intervals specified by the ITE Determining Vehicle Change Intervals: A Proposed Recommended Practice (1985)] Fatal/ Injury Signal empty cell 4-leg 12(9)30 empty cell -6(22)30 -8(17)30 empty cell empty cell empty cell
Improve signal timing [to intervals specified by the ITE Determining Vehicle Change Intervals: A Proposed Recommended Practice (1985)] Fatal/ Injury Signal All empty cell empty cell empty cell empty cell empty cell empty cell f 911 empty cell
Improve signal timing [to intervals specified by the ITE Determining Vehicle Change Intervals: A Proposed Recommended Practice (1985)] Fatal/ Injury empty cell empty cell empty cell empty cell empty cell empty cell empty cell empty cell r 3730 empty cell
Improve signal timing [to intervals specified by the ITE Determining Vehicle Change Intervals: A Proposed Recommended Practice (1985)] PDO empty cell empty cell empty cell empty cell 639 469 174 empty cell b 284 empty cell
Increase yellow change interval All Signal empty cell empty cell 159 empty cell 309 empty cell empty cell empty cell empty cell
Install emergency vehicle pre-emption systems All empty cell empty cell empty cell empty cell empty cell empty cell empty cell empty cell u 7031 empty cell
Modify signal phasing (implement a leading pedestrian interval) All Signal empty cell empty cell empty cell empty cell empty cell empty cell empty cell r 516 empty cell
Provide actuated signals All Signal empty cell empty cell empty cell 809 109 empty cell empty cell empty cell empty cell
Provide Advanced Dilemma Zone Detection for rural high-speed approaches Fatal/ Injury Signal Rural 4-leg (1 app) 3940 empty cell empty cell empty cell empty cell empty cell empty cell
Provide protected left-turn phase Fatal/ Injury Signal Urban empty cell empty cell 17(4)43 25(2)43 empty cell empty cell empty cell empty cell
Provide protected left-turn phase All Signal empty cell empty cell 309 419 549 279 empty cell c 279 <5,000/ lane (Total)
Provide protected left-turn phase All Signal empty cell empty cell 369 469 569 359 empty cell c 359 <5,000/ lane (Total)
Provide protected left-turn phase All Signal empty cell empty cell 279 489 639 319 empty cell c 319 empty cell
Provide protected/ permissive left-turn phase (leading green arrow) Fatal/ Injury Signal Urban empty cell empty cell 17(2)19 25(2)19 empty cell empty cell empty cell empty cell
Provide signal coordination All Signal empty cell empty cell empty cell empty cell 3216 empty cell empty cell empty cell empty cell
Provide split phases All Signal empty cell empty cell 2516 empty cell empty cell empty cell empty cell empty cell empty cell
Remove flash mode (late night/ early morning) All Signal empty cell empty cell 2916 empty cell 75(19)28 empty cell empty cell empty cell empty cell
Replace existing WALK/ DON'T WALK signals with pedestrian countdown signal heads All Signal Urban empty cell empty cell empty cell empty cell empty cell empty cell r 2520 empty cell
Signal Hardware Countermeasures
Add 3-inch yellow retroreflective sheeting to signal backplates All Signal Urban empty cell 15(51)33 empty cell empty cell empty cell empty cell empty cell empty cell
Add additional signal and upgrade to 12-inch lenses All Signal empty cell 4-leg empty cell empty cell empty cell empty cell empty cell h 3125 empty cell
Add additional signal and upgrade to 12-inch lenses All Signal empty cell 4-leg empty cell empty cell empty cell empty cell empty cell i 1725 empty cell
Add signal (additional primary head) All Signal Urban 4-leg 287 empty cell 357 287 empty cell empty cell empty cell
Add signal (additional primary head) Fatal/ Injury Signal Urban 4-leg 177 empty cell empty cell empty cell empty cell empty cell empty cell
Add signal (additional primary head) PDO Signal Urban 4-leg 317 empty cell empty cell empty cell empty cell empty cell empty cell
Convert signal from pedestal-mounted to mast arm All Signal empty cell empty cell 4931 1231 7431 4131 empty cell empty cell empty cell
Convert signal from pedestal-mounted to mast arm Fatal/ Injury Signal empty cell empty cell 4431 empty cell empty cell empty cell empty cell empty cell empty cell
Convert signal from pedestal-mounted to mast arm PDO Signal empty cell empty cell 5131 empty cell empty cell empty cell empty cell empty cell empty cell
Improve visibility of signal heads (increase signal lens size, install new backboards, add reflective tape to existing backboards, and/or install additional signal heads) All Signal Urban empty cell 735 empty cell empty cell empty cell empty cell d 635 empty cell
Improve visibility of signal heads (increase signal lens size, install new backboards, add reflective tape to existing backboards, and/or install additional signal heads) All Signal Urban empty cell empty cell empty cell empty cell empty cell empty cell e 635 empty cell
Improve visibility of signal heads (increase signal lens size, install new backboards, add reflective tape to existing backboards, and/or install additional signal heads) Fatal/ Injury Signal Urban empty cell 335 empty cell empty cell empty cell empty cell empty cell empty cell
Improve visibility of signal heads (increase signal lens size, install new backboards, add reflective tape to existing backboards, and/or install additional signal heads) PDO Signal Urban empty cell 918 empty cell empty cell empty cell empty cell empty cell empty cell
Improve visibility of signal heads (install two red displays in each head) All Signal empty cell empty cell 916 empty cell 3616 empty cell empty cell empty cell empty cell
Install larger signal lenses (12 inch) All Signal empty cell empty cell 1116 empty cell 4628 empty cell empty cell empty cell empty cell
Install larger signal lenses (12 inch) All Signal Urban empty cell 2433 empty cell empty cell empty cell empty cell empty cell empty cell
Install larger signal lenses (12 inch) Fatal/ Injury Signal Urban empty cell 1633 empty cell empty cell empty cell empty cell empty cell empty cell
Install signal backplates only All Signal empty cell empty cell 1316 empty cell 5016 empty cell empty cell empty cell empty cell
Install signal backplates (or visors) All Signal empty cell empty cell empty cell empty cell 209 empty cell empty cell empty cell empty cell
Install signals All No Signal empty cell empty cell 3316 3826 empty cell empty cell empty cell j 5026 empty cell
Install signals All No Signal empty cell empty cell 389 empty cell 749 229 empty cell c 229 <5,000/ lane (Total)
Install signals All No Signal empty cell empty cell 209 empty cell 439 209 empty cell c 209 >5,000/ lane (Total)
Install signals All No Signal Rural empty cell 1526 empty cell empty cell empty cell empty cell empty cell empty cell
Install signals All Stop Urban 4-leg 5(9)43 empty cell 67(6)43 -143(40)43 empty cell empty cell empty cell
Install signals All Stop Rural 3-leg or 4-leg 44(3)43 60(6)43 77(2)43 -58(20)43 empty cell empty cell 3,300-30,000/ 100-10,300
Install signals Fatal No Signal empty cell empty cell 3826 empty cell empty cell empty cell empty cell empty cell empty cell
Install signals Fatal/ Injury Stop Urban 3-leg 14(32)21 empty cell 34(45)21 -50(51)21 empty cell empty cell 11,750-42,000/ 900-4000
Install signals Fatal/ Injury Stop Urban 4-leg 23(22)21 empty cell 67(20)21 -38(39)21 empty cell empty cell 12,650- 22,400/ 2,400- 3,625
Install signals PDO No Signal empty cell empty cell -1513 empty cell empty cell empty cell empty cell empty cell empty cell
Install signals (temporary) Fatal/ Injury No Signal empty cell empty cell empty cell empty cell 399 empty cell 504 empty cell empty cell
Install signals (temporary) PDO No Signal empty cell empty cell empty cell 119 739 empty cell empty cell a 839 empty cell
Install signals (to have one over each approach lane) All empty cell All empty cell empty cell empty cell 463 empty cell empty cell empty cell empty cell
Remove unwarranted signals All Signal Urban empty cell 24(9)43 empty cell 24(10)43 29(20)43 empty cell d 3011 empty cell
Remove unwarranted signals All Signal Urban empty cell empty cell empty cell empty cell empty cell empty cell e 2211 empty cell
Remove unwarranted signals All Signal Urban empty cell empty cell empty cell empty cell empty cell empty cell g 3111 empty cell
Remove unwarranted signals Fatal/ Injury Signal Urban empty cell 5311 empty cell empty cell empty cell empty cell empty cell empty cell
Remove unwarranted signals PDO Signal Urban empty cell 2411 empty cell empty cell empty cell empty cell empty cell empty cell
Remove unwarranted signals Pedestrian Signal Urban One-lane one-way streets excluding major arterials 18(30)43 empty cell empty cell empty cell empty cell empty cell empty cell
Replace signal lenses with optical lenses All Signal empty cell empty cell 1716 109 109 109 empty cell a 209 empty cell
Combination Signal and Other Countermeasures
Install left turn lane and add turn phase All Signal empty cell empty cell 5816 empty cell empty cell empty cell empty cell empty cell empty cell
Install signals and add channelization PDO No Signal empty cell empty cell empty cell 249 639 empty cell empty cell a 279 empty cell
Install signals and add channelization Fatal/ Injury No Signal empty cell empty cell empty cell empty cell 679 empty cell 549 b 359 empty cell


Table 2. Geometric Countermeasures
Countermeasure Crash Severity Control Area Type Config- uration All Crashes Left-Turn Crashes Rt-Angle Crashes Rear-end Crashes Sideswipe Crashes Other Crashes Major/ Minor Daily Traffic Volume (veh/day)
Left Turn Countermeasures
empty cell All Stop empty cell empty cell 18(8)38 empty cell empty cell empty cell empty cell empty cell >34,000
empty cell All Stop empty cell empty cell -24 (35)38 empty cell empty cell empty cell empty cell empty cell >34,000/4 lanes
empty cell All Stop empty cell empty cell 26 (8)38 empty cell empty cell empty cell empty cell empty cell >34,000/6 lanes
empty cell All Stop empty cell empty cell 24 (63)38 empty cell empty cell empty cell empty cell empty cell >34,000/8 lanes
empty cell Fatal/ Injury Stop empty cell empty cell 27 (12)38 empty cell empty cell empty cell empty cell empty cell >34,000
empty cell PDO Stop empty cell empty cell 6 (11)38 empty cell empty cell empty cell empty cell empty cell >34,000
Create directional median openings to allow left turns and u-turns All Signal empty cell empty cell 5131 empty cell empty cell empty cell empty cell empty cell empty cell
Install left-turn lane All Signal Rural 3-Leg 1514 empty cell empty cell empty cell empty cell empty cell 4,200-26,000/ 1,300-11,400
Install left-turn lane All Signal Rural 4-Leg (1 app) 1814 empty cell empty cell empty cell empty cell empty cell 4,200-26,000/ 1,300-11,400
Install left-turn lane All Signal Rural 4-Leg (2app) 3343 empty cell empty cell empty cell empty cell empty cell empty cell
Install left-turn lane All Signal Urban 3-Leg 714 empty cell empty cell empty cell empty cell empty cell 4,600-55,000/ 100-26,000
Install left-turn lane All Signal Urban 4-Leg (1 app) 10(10)43 1311 empty cell empty cell empty cell empty cell 7,200-55,100/ 350-2,600
Install left-turn lane All Signal Urban 4-Leg (2 apps) 19(10)43 2411 empty cell empty cell empty cell empty cell 7,200-55,100/ 350-2,600
Install left-turn lane All Stop Rural 3-Leg 44(6)43 6211 empty cell empty cell empty cell empty cell 1,600-32,400/ 50-11,800
Install left-turn lane All Stop Rural 4-Leg (1 app) 28(3)43 3711 empty cell empty cell empty cell empty cell 1,600-32,400/ 50-11,800
Install left-turn lane All Stop Rural 4-Leg (2 apps) 48(3)43 6011 empty cell empty cell empty cell empty cell 1,600-32,400/ 50-11,800
Install left-turn lane All Stop Urban 3-Leg 33(20)43 empty cell empty cell empty cell empty cell empty cell 1,520-40,600/ 200-8,000
Install left-turn lane All Stop Urban 4-Leg (1 app) 27(3)43 2611 empty cell empty cell empty cell empty cell 1,520-40,600/ 200-8,000
Install left-turn lane All Stop Urban 4-Leg (2 apps) 47(4)43 4511 empty cell empty cell empty cell empty cell 1,520-40,600/ 200-8,000
Install left-turn lane Fatal/ Injury Signal Urban 3-Leg ; on 1 major road app. 643 empty cell empty cell empty cell empty cell empty cell empty cell
Install left-turn lane Fatal/ Injury Signal Urban 4-leg (1 app) 9(2)43 empty cell empty cell empty cell empty cell empty cell 7,200-55,100/ 350-2,600
Install left-turn lane Fatal/ Injury Signal Urban 4-leg (2 apps) 17(2)43 empty cell empty cell empty cell empty cell empty cell 7,200-55,100/ 350-2,600
Install left-turn lane Fatal/ Injury Stop Rural 3-Leg 55(10)43 empty cell empty cell empty cell empty cell empty cell 1,600-32,400/ 50-11,800
Install left-turn lane Fatal/ Injury Stop Rural 4-Leg (1 app) 35(3)43 empty cell empty cell empty cell empty cell empty cell 1,600-32,400/ 50-11,800
Install left-turn lane Fatal/ Injury Stop Rural 4-Leg (2 apps) 58(4)43 empty cell empty cell empty cell empty cell empty cell 1,600-32,400/ 50-11,800
Install left-turn lane Fatal/ Injury Stop Urban 3-Leg; on 1 major road app. 3543 empty cell empty cell empty cell empty cell empty cell empty cell
Install left-turn lane Fatal/ Injury Stop Urban 4-Leg (1 app) 29(4)43 empty cell empty cell empty cell empty cell empty cell 1,520-40,600/ 200-8,000
Install left-turn lane Fatal/ Injury Stop Urban 4-Leg (2 apps) 50(6)43 empty cell empty cell empty cell empty cell empty cell 1,520-40,600/ 200-8,000
Install left turn lane on newly signalized intersection All Newly Signalized Urban 4-Leg (1 app) 24(3)43 empty cell empty cell empty cell empty cell empty cell 4,600 to 40,300/100 to 13,700
Install left turn lane on newly signalized intersection Fatal/ Injury Newly Signalized Urban 4-Leg (1 app) 28(6)43 empty cell empty cell empty cell empty cell empty cell 4,600 to 40,300/100 to 13,700
Install left turn lane on newly signalized intersection All Newly Signalized Urban 4-Leg (2 apps) 42(4)43 empty cell empty cell empty cell empty cell empty cell 4,600 to 40,300/100 to 13,700
Install left turn lane on newly signalized intersection Fatal/ Injury Newly Signalized Urban 4-Leg (2 apps) 48(7)43 empty cell empty cell empty cell empty cell empty cell 4,600 to 40,300/100 to 13,700
Install left-turn lane (double) Fatal/ Injury Undefined empty cell empty cell empty cell 479 209 299 509 a 759 empty cell
Install left-turn lane (double) PDO Undefined empty cell empty cell empty cell 719 89 329 empty cell b 139 empty cell
Install left-turn lane painted separation All Undefined empty cell empty cell 509 579 629 549 empty cell c 549 <5,000/lane (Total)
Install left-turn lane painted separation All Undefined empty cell empty cell empty cell 359 499 399 empty cell c 399 >5,000/lane (Total)
Install left-turn lane painted separation Fatal/ Injury Undefined Mostly rural 3-Leg 22(14)6 empty cell empty cell empty cell empty cell empty cell 5,000-15,000
Install left-turn lane painted separation Fatal/ Injury Undefined Mostly rural 4-Leg -18(27)6 empty cell empty cell empty cell empty cell empty cell 5,000-15,000
Install left-turn lane painted separation PDO Undefined Mostly rural 3-Leg 20(19)6 empty cell empty cell empty cell empty cell empty cell 5,000-15,000
Install left-turn lane painted separation PDO Undefined Mostly rural 4-Leg 26(12)6 empty cell empty cell empty cell empty cell empty cell 5,000-15,000
Install left-turn lane (physical channelization) All No signal empty cell 4-Leg (2 apps) 4216 empty cell empty cell empty cell empty cell empty cell empty cell
Install left-turn lane (physical channelization) All No signal Rural 3-Leg 4416 empty cell empty cell empty cell empty cell empty cell empty cell
Install left-turn lane (physical channelization) All No signal empty cell 4-Leg (1 app) 2816 empty cell empty cell empty cell empty cell empty cell empty cell
Install left-turn lane (physical channelization) All No signal empty cell 3-Leg 3316 empty cell empty cell empty cell empty cell empty cell empty cell
Install left-turn lane (physical channelization) All No signal empty cell 4-Leg (1 app) 2716 empty cell empty cell empty cell empty cell empty cell empty cell
Install left-turn lane (physical channelization) All Undefined empty cell empty cell 519 249 689 509 empty cell c 509 <5,000/lane (Total)
Install left-turn lane (physical channelization) All Undefined empty cell empty cell 199 249 559 289 empty cell c 289 >5,000/lane (Total)
Install left-turn lane (physical channelization) Fatal/ Injury Undefined empty cell empty cell empty cell 509 589 119 empty cell empty cell empty cell
Install left-turn lane (physical channelization) Fatal/ Injury Undefined Rural 4-Leg (major road apps.) 4(20)43 empty cell empty cell empty cell empty cell empty cell 5,000-15,000
Install left-turn lane (physical channelization) Fatal/ Injury Signalized, minor road stop controlled, and all way stop controlled Rural 4-Leg (all apps) 27(10)43 empty cell empty cell empty cell empty cell empty cell 5,000 to 15,000
Install left-turn lane (physical channelization) Fatal/ Injury Signalized, minor road stop controlled, and all way stop controlled Rural 3-Leg (1 app) 27(20)43 empty cell empty cell empty cell empty cell empty cell 5,000 to 15,000
Install left-turn lane (physical channelization) Fatal/ Injury Signalized, minor road stop controlled, and all way stop controlled Rural 3-Leg (2 app) -16(20)43 empty cell empty cell empty cell empty cell empty cell 5,000 to 15,000
Install left-turn lane (physical channelization) PDO Undefined empty cell empty cell empty cell empty cell 549 569 empty cell b 509 empty cell
Install left-turn lane (physical channelization) PDO Undefined Rural 3-Leg -20(23)6 empty cell empty cell empty cell empty cell empty cell 5,000 to 15,000
Install left-turn lane (physical channelization) PDO Undefined Rural 4-Leg 16(22)6 empty cell empty cell empty cell empty cell empty cell 5,000 to 15,000
Install left-turn lane (signal has left-turn phase) All Signal empty cell empty cell 3116 4416 empty cell empty cell empty cell empty cell empty cell
Install left-turn lane (signal has left-turn phase) All Signal empty cell 4-Leg empty cell empty cell empty cell empty cell empty cell h 7325 empty cell
Install left-turn lane (signal has left-turn phase) All Signal empty cell 4-Leg empty cell empty cell empty cell empty cell empty cell i 6625 empty cell
Install left-turn lane (signal has no turn phase) All Signal empty cell empty cell 2316 5016 empty cell empty cell empty cell empty cell empty cell
Install left-turn lane (with channelization and existing left-turn phase) All Signal empty cell empty cell 369 empty cell empty cell empty cell empty cell empty cell empty cell
Install left-turn lane (with channelization and no left-turn phase) All Undefined empty cell empty cell 159 empty cell empty cell empty cell empty cell empty cell empty cell
Install left-turn lane within existing curbs All Signal empty cell empty cell 2616 6616 empty cell empty cell empty cell empty cell empty cell
Install left-turn refuge within flush median All Undefined empty cell empty cell 249 empty cell empty cell 449 empty cell c 449 <5,000/lane (Total)
Install left-turn refuge within flush median All Undefined empty cell empty cell 449 779 empty cell 409 529 a 529 >5,000/lane (Total)
Install left-turn refuge within flush median All Undefined empty cell empty cell empty cell empty cell empty cell empty cell empty cell c 409 >5,000/lane (Total)
Remove left-turn lane All Signal Rural 3-Leg -183 empty cell empty cell empty cell empty cell empty cell empty cell
Remove left-turn lane All Signal Rural 4-Leg (1 app) -223 empty cell empty cell empty cell empty cell empty cell empty cell
Remove left-turn lane All Signal Rural 4-Leg (2 apps) -493 empty cell empty cell empty cell empty cell empty cell empty cell
Remove left-turn lane All Signal Urban 3-Leg -83 empty cell empty cell empty cell empty cell empty cell empty cell
Remove left-turn lane All Signal Urban 4-Leg (2 app) -113 empty cell empty cell empty cell empty cell empty cell empty cell
Remove left-turn lane All Signal Urban 4-Leg (2 apps) -233 empty cell empty cell empty cell empty cell empty cell empty cell
Remove left-turn lane All Stop Urban 3-Leg -493 empty cell empty cell empty cell empty cell empty cell empty cell
Remove left-turn lane All Stop Urban 4-Leg (1 app) -373 empty cell empty cell empty cell empty cell empty cell empty cell
Remove left-turn lane All Stop Urban 4-Leg (2 apps) -883 empty cell empty cell empty cell empty cell empty cell empty cell
Remove left-turn lane Fatal/ Injury Signal Rural 3-Leg -163 empty cell empty cell empty cell empty cell empty cell empty cell
Remove left-turn lane Fatal/ Injury Signal Rural 4-Leg (1 app) -213 empty cell empty cell empty cell empty cell empty cell empty cell
Remove left-turn lane Fatal/ Injury Signal Rural 4-Leg (2 apps) -453 empty cell empty cell empty cell empty cell empty cell empty cell
Remove left-turn lane Fatal/ Injury Signal Urban 3-Leg -63 empty cell empty cell empty cell empty cell empty cell empty cell
Remove left-turn lane Fatal/ Injury Signal Urban 4-Leg (1 app) -103 empty cell empty cell empty cell empty cell empty cell empty cell
Remove left-turn lane Fatal/ Injury Signal Urban 4-Leg (2 apps) -213 empty cell empty cell empty cell empty cell empty cell empty cell
Remove left-turn lane Fatal/ Injury Stop Urban 3-Leg -533 empty cell empty cell empty cell empty cell empty cell empty cell
Remove left-turn lane Fatal/ Injury Stop Urban 4-Leg (1 app) -413 empty cell empty cell empty cell empty cell empty cell empty cell
Remove left-turn lane Fatal/ Injury Stop Urban 4-Leg (2 apps) -983 empty cell empty cell empty cell empty cell empty cell empty cell
Right Turn Countermeasures
Increase length of right-turn lane Fatal/ Injury All All All 1537 empty cell empty cell empty cell empty cell empty cell empty cell
Install right-turn lane All Signal All 4-Leg or 3 leg (1 app) 4(2)43 empty cell empty cell empty cell empty cell empty cell 7,200-55,100 / 550-26,000
Install right-turn lane All Stop All 4-Leg (1 app) 14(5)43 empty cell empty cell empty cell empty cell empty cell 1,520-40,600 / 25-26,000
Install right-turn lane All Signal All 4-Leg (2 apps) 8(3)43 empty cell empty cell empty cell empty cell empty cell 7,200-55,100 / 550-26,000
Install right-turn lane All Stop All 4-Leg (2 apps) 26(7)43 empty cell empty cell empty cell empty cell empty cell 1,520-40,600 / 25-26,000
Install right-turn lane Fatal/ Injury Signal All 4-Leg or 3 leg (1 app) 9(3)43 empty cell empty cell empty cell empty cell empty cell 7,200-55,100 / 550-26,000
Install right-turn lane Fatal/ Injury Stop All 4-Leg or 3 leg (1 app) 23(7)43 empty cell empty cell empty cell empty cell empty cell 1,520-40,600 / 25-26,000
Install right-turn lane All Undefined empty cell empty cell empty cell empty cell empty cell empty cell empty cell empty cell empty cell
Provide a right-turn lane on both major road approaches Fatal/ Injury Stop All 4-Leg 4143 empty cell empty cell empty cell empty cell empty cell empty cell
Provide a right-turn lane on both major road approaches Fatal/ Injury Signal All 4-Leg 1743 empty cell empty cell empty cell empty cell empty cell empty cell
Install right-turn lane (painted separation) Fatal/ Injury All All All 3037 empty cell empty cell empty cell empty cell empty cell empty cell
Install left-turn lane (physical channelization) Fatal/ Injury All All All 3537 empty cell empty cell empty cell empty cell empty cell empty cell
Other Geometric Countermeasures
Convert 4-Leg to two T-intersections Fatal/ Injury Undefined Urban 4-Leg 33(10)43 empty cell empty cell empty cell empty cell empty cell <70% / >30%
Convert 4-Leg to two T-intersections Fatal/ Injury Undefined Urban 4-Leg -35(30)43 empty cell empty cell empty cell empty cell empty cell >85% / <15%
Convert 4-Leg to two T-intersections Fatal/ Injury Undefined Urban 4-Leg 25(8)43 empty cell empty cell empty cell empty cell empty cell 70-85% / 15-30%
Convert 4-Leg to two T-intersections PDO Undefined Urban 4-Leg 10(9)43 empty cell empty cell empty cell empty cell empty cell <70% / >30%
Convert 4-Leg to two T-intersections PDO Undefined Urban 4-Leg -15(10)43 empty cell empty cell empty cell empty cell empty cell >85% / <15%
Convert 4-Leg to two T-intersections PDO Undefined Urban 4-Leg 0(9)43 empty cell empty cell empty cell empty cell empty cell 70-85% / 15-30%
Convert intersection to roundabout All All All empty cell 35(3)32 empty cell empty cell empty cell empty cell empty cell empty cell
Convert intersection to roundabout All Signal All empty cell 48(5)43 empty cell empty cell empty cell empty cell empty cell empty cell
Convert intersection to roundabout All Stop (2-way) All empty cell 44(4)43 empty cell empty cell empty cell empty cell empty cell empty cell
Convert intersection to roundabout All Stop (4-way) All empty cell -3(15)32 empty cell empty cell empty cell empty cell empty cell empty cell
Convert intersection to roundabout All Stop (2-way) Rural 1-lane 71(4)43 empty cell empty cell empty cell empty cell empty cell empty cell
Convert intersection to roundabout All Signal Urban empty cell 1(12)32 empty cell empty cell empty cell empty cell empty cell empty cell
Convert intersection to roundabout All Stop (2-way) Urban empty cell 29(10)43 empty cell empty cell empty cell empty cell empty cell empty cell
Convert intersection to roundabout All Stop (2-way) Urban 1-lane 39(10)43 empty cell empty cell empty cell empty cell empty cell empty cell
Convert intersection to roundabout All Signal Urban 2-lanes 67(4)32 empty cell empty cell empty cell empty cell empty cell empty cell
Convert intersection to roundabout All Stop (2-way) Urban 2-lanes 12(20)43 empty cell empty cell empty cell empty cell empty cell empty cell
Convert intersection to roundabout Fatal/ Injury All All empty cell 76(3)32 empty cell empty cell empty cell empty cell empty cell empty cell
Convert intersection to roundabout Fatal/ Injury Signal All empty cell 78(6)32 empty cell empty cell empty cell empty cell empty cell empty cell
Convert intersection to roundabout Fatal/ Injury Stop (2-way) All empty cell 82(3)43 empty cell empty cell empty cell empty cell empty cell empty cell
Convert intersection to roundabout Fatal/ Injury Stop (4-way) All empty cell -28(41)32 empty cell empty cell empty cell empty cell empty cell empty cell
Convert intersection to roundabout Fatal/ Injury Stop (2-way) Rural 1-lane 87(3)32 empty cell empty cell empty cell empty cell empty cell empty cell
Convert intersection to roundabout Fatal/ Injury Signal Urban empty cell 60(12)32 empty cell empty cell empty cell empty cell empty cell empty cell
Convert intersection to roundabout Fatal/ Injury Stop (2-way) Urban empty cell 81(10)43 empty cell empty cell empty cell empty cell empty cell empty cell
Convert intersection to roundabout Fatal/ Injury Stop (2-way) Urban 1-lane 78(7)32 empty cell empty cell empty cell empty cell empty cell empty cell
Convert intersection to roundabout Fatal/ Injury Stop (2-way) Urban 2-lane 72(9)32 empty cell empty cell empty cell empty cell empty cell empty cell
Convert intersection to roundabout All Stop (2-way) Suburban empty cell 32(8)43 empty cell empty cell empty cell empty cell empty cell empty cell
Convert intersection to roundabout All Stop (2-way) Suburban 1-lane 78(7)43 empty cell empty cell empty cell empty cell empty cell empty cell
Convert intersection to roundabout All Stop (2-way) Suburban 2-lane 19(10)43 empty cell empty cell empty cell empty cell empty cell empty cell
Convert intersection to roundabout Fatal/ Injury Stop (2-way) Suburban empty cell 71(10)43 empty cell empty cell empty cell empty cell empty cell empty cell
Convert intersection to roundabout Fatal/ Injury Stop (2-way) Suburban 1-lane 78(10)43 empty cell empty cell empty cell empty cell empty cell empty cell
Convert intersection to roundabout Fatal/ Injury Stop (2-way) Suburban 2-lane 68(10)43 empty cell empty cell empty cell empty cell empty cell empty cell
Convert intersection to roundabout All Stop/ Yield (2-way) Rural 4-Leg 513 empty cell empty cell empty cell empty cell empty cell empty cell
Convert intersection to roundabout All Stop/ Yield (2-way) Rural 4-Leg 913 empty cell empty cell empty cell empty cell empty cell empty cell
Convert intersection to roundabout All Stop/ Yield (2-way) Rural 4-Leg 1313 empty cell empty cell empty cell empty cell empty cell empty cell
Convert intersection to roundabout All Stop/ Yield (2-way) Rural 4-Leg 1713 empty cell empty cell empty cell empty cell empty cell empty cell
Convert intersection to roundabout All Signal Rural 4-Leg 013 empty cell empty cell empty cell empty cell empty cell empty cell
Convert intersection to roundabout All Stop Rural 4-Leg empty cell empty cell empty cell empty cell empty cell empty cell empty cell
Convert intersection to roundabout All Stop Urban 3-Leg empty cell empty cell empty cell empty cell empty cell empty cell empty cell
Convert intersection to roundabout All Signal Urban 4-Leg empty cell empty cell empty cell empty cell empty cell f 4(1)12 empty cell
Convert intersection to roundabout All Stop Urban 4-Leg empty cell empty cell empty cell empty cell empty cell f -3(1)12 empty cell
Convert intersection to roundabout Fatal/ Injury Stop Rural 4-Leg empty cell empty cell empty cell empty cell empty cell f -6(1)43 empty cell
Convert intersection to roundabout Fatal/ Injury Signal Urban 4-Leg empty cell empty cell empty cell empty cell empty cell f 4(2)43 empty cell
Convert intersection to roundabout Fatal/ Injury Stop Urban 4-Leg empty cell empty cell empty cell empty cell empty cell f -3(1)43 empty cell
Convert intersection to roundabout Fatal/ Injury Undefined empty cell empty cell -12(126)3 empty cell empty cell empty cell empty cell f -5(2)43 empty cell
Install median All Stop Rural empty cell 273 empty cell empty cell empty cell empty cell empty cell empty cell
Install median islands (painted) on major road approaches Fatal/ Injury All All All 1537 empty cell empty cell empty cell empty cell empty cell empty cell
Install median islands (physical) on major road approaches Fatal/ Injury All All All 2516 empty cell empty cell empty cell empty cell empty cell empty cell
Install raised median All No Signal empty cell empty cell empty cell empty cell empty cell empty cell empty cell empty cell empty cell
Install raised median (marked crosswalk) All No Signal empty cell empty cell empty cell empty cell empty cell empty cell empty cell r 4638 empty cell
Install raised median (unmarked crosswalk) All No Signal empty cell empty cell empty cell empty cell empty cell empty cell empty cell r 3938 empty cell
Install refuge islands All Undefined empty cell empty cell empty cell empty cell empty cell empty cell empty cell r 5616 empty cell
Install splitter islands on minor road approaches Fatal/ Injury All All 3-Leg 4537 empty cell empty cell empty cell empty cell empty cell empty cell
Install splitter islands on minor road approaches Fatal/ Injury All All 4-Leg 4037 empty cell empty cell empty cell empty cell empty cell empty cell
Install splitter islands on minor road approaches Fatal/ Injury All All All 4037 empty cell empty cell empty cell empty cell empty cell empty cell
Install splitter islands on minor road approaches Fatal/ Injury All Rural All 3537 empty cell empty cell empty cell empty cell empty cell empty cell
Install splitter islands on minor road approaches Fatal/ Injury All Urban All 4037 empty cell empty cell empty cell empty cell empty cell empty cell
Install turn and bypass lanes All Stop Rural empty cell 5(10)29 empty cell empty cell empty cell empty cell empty cell empty cell
Install turn and bypass lanes Injury Undefined empty cell 3-Leg empty cell 369 249 189 empty cell empty cell empty cell
Install turn and bypass lanes PDO Undefined empty cell 3-Leg empty cell 289 539 219 309 a 139 empty cell
Install turn and bypass lanes PDO Undefined empty cell 3-Leg empty cell empty cell empty cell empty cell empty cell b 409 empty cell



Table 3. Signs/Markings/Operational Countermeasures
Countermeasure Crash Severity Control Area Type Config- uration All Crashes Left-Turn Crashes Rt-Angle Crashes Rear-end Crashes Sideswipe Crashes Other Crashes Major/ Minor Daily Traffic Volume (veh/day)
Signs
Install double stop signs All No Signal empty cell empty cell 1116 empty cell 55(52)28 empty cell empty cell empty cell empty cell
Install flashing beacons as advance warning All Undefined empty cell 3-Leg 709 empty cell empty cell empty cell empty cell empty cell empty cell
Install flashing beacons as advance warning All Undefined empty cell 4-Leg 399 empty cell empty cell empty cell empty cell empty cell empty cell
Install flashing beacons as advance warning All Signal empty cell empty cell 2716 empty cell empty cell empty cell empty cell empty cell empty cell
Install flashing beacons as advance warning Fatal/ Injury Undefined empty cell empty cell empty cell 679 739 empty cell empty cell empty cell empty cell
Install flashing beacons as advance warning PDO Undefined empty cell empty cell empty cell 799 629 empty cell empty cell empty cell empty cell
Install flashing beacons as advance warning All Signal empty cell 4-Leg empty cell empty cell 6225 3625 empty cell empty cell empty cell
Install flashing beacons at stop controlled intersections All Stop All 4-Leg 5(4)43 empty cell empty cell empty cell empty cell empty cell empty cell
Install flashing beacons at stop controlled intersections Injury Stop All 4-Leg 10(6)43 empty cell empty cell empty cell empty cell empty cell empty cell
Install flashing beacons at stop controlled intersections All Stop All 4-Leg empty cell empty cell empty cell 8(10)43 empty cell empty cell empty cell
Install flashing beacons at stop controlled intersections All Stop All 4-Leg empty cell empty cell 13(6)43 empty cell empty cell empty cell empty cell
Install flashing beacons at stop controlled intersections All Stop Rural 4-Leg empty cell empty cell 16(6)43 empty cell empty cell empty cell empty cell
Install flashing beacons at stop controlled intersections All Stop Suburban 4-Leg empty cell empty cell 12(10)43 empty cell empty cell empty cell empty cell
Install flashing beacons at stop controlled intersections All Stop Urban 4-Leg empty cell empty cell -12(30)43 empty cell empty cell empty cell empty cell
Install flashing beacons at stop controlled intersections All Stop (2-way) All 4-Leg empty cell empty cell 13(6)43 empty cell empty cell empty cell empty cell
Install flashing beacons at stop controlled intersections All Stop (4-way) All 4-Leg empty cell empty cell 28(20)43 empty cell empty cell empty cell empty cell
Install flashing beacons at stop controlled intersections All Standard Overhead Beacon All 4-Leg empty cell empty cell 12(6)43 empty cell empty cell empty cell empty cell
Install flashing beacons at stop controlled intersections All Standard Mounted Beacon All 4-Leg empty cell empty cell 58(20)43 empty cell empty cell empty cell empty cell
Install flashing beacons at stop controlled intersections All Standard Overhead and Stop-Mounted Beacon All 4-Leg empty cell empty cell 13(6)43 empty cell empty cell empty cell empty cell
Install flashing beacons at stop controlled intersections All Actuated Beacon All 4-Leg empty cell empty cell 14(10)43 empty cell empty cell empty cell empty cell
Install larger stop signs All Stop empty cell empty cell 199 empty cell empty cell empty cell empty cell empty cell >5,000/ lane (Total)
Install pedestrian signing All Undefined empty cell empty cell 49 empty cell empty cell empty cell empty cell empty cell empty cell
Install pedestrian signing All Undefined empty cell empty cell empty cell empty cell empty cell empty cell empty cell r 159 empty cell
Install advance warning signs (positive guidance) All Signal empty cell empty cell 2216 empty cell 35(1)28 empty cell empty cell empty cell empty cell
Install advance warning signs (positive guidance) All Undefined Urban empty cell 309 empty cell empty cell empty cell empty cell empty cell empty cell
Install advance warning signs (positive guidance) All Undefined Rural empty cell 409 empty cell empty cell empty cell empty cell empty cell empty cell
Provide overhead lane-use signs All Undefined empty cell empty cell 1031 empty cell empty cell empty cell empty cell empty cell empty cell
Provide overhead lane-use signs All Undefined empty cell empty cell 2031 empty cell empty cell empty cell empty cell empty cell empty cell
Pavement Markings/Modifications
Add centerline and move Stop bar to extended curb lines All No Signal empty cell empty cell 2916 empty cell 2416 empty cell empty cell empty cell empty cell
Add centerline and move Stop bar to extended curb lines; double Stop signs All No Signal empty cell empty cell 916 empty cell 016 empty cell empty cell empty cell empty cell
Add centerline and Stop bar, replace 24-inch with 30-inch stop signs All No Signal empty cell empty cell empty cell empty cell 67(11)28 empty cell empty cell empty cell empty cell
Improve pavement friction (groove) All Undefined empty cell empty cell 2516 empty cell empty cell empty cell empty cell p 5916 empty cell
Improve/install pedestrian crossing All Undefined empty cell empty cell empty cell empty cell empty cell empty cell empty cell r 259 empty cell
Install pedestrian crossing Fatal/ Injury Undefined Rural empty cell empty cell empty cell empty cell empty cell empty cell r 6024 empty cell
Install pedestrian crossing (raised) All Undefined empty cell empty cell 30(67)2 empty cell empty cell empty cell empty cell empty cell empty cell
Install pedestrian crossing (raised) Fatal/ Injury Undefined empty cell empty cell 36(54)2 empty cell empty cell empty cell empty cell empty cell empty cell
Install raised intersection Fatal/ Injury Undefined empty cell 4-Leg -56 empty cell empty cell empty cell empty cell empty cell empty cell
Install raised intersection PDO Undefined empty cell 4-Leg -136 empty cell empty cell empty cell empty cell empty cell empty cell
Install raised pavement markers All Undefined empty cell empty cell 1016 empty cell empty cell empty cell empty cell p 2516 empty cell
Install raised pavement markers All Undefined empty cell empty cell empty cell empty cell empty cell empty cell empty cell q 3316 empty cell
Install Stop bars (pedestrian crosswalk) All Signal empty cell empty cell 1816 empty cell empty cell empty cell empty cell empty cell empty cell
Install Stop bars (Stop bar on minor road approaches with short sebments of centerline) All Undefined empty cell empty cell 1916 empty cell empty cell empty cell empty cell empty cell empty cell
Install Stop bars (Stop bar on minor road approaches with short sebments of centerline) All Undefined empty cell empty cell empty cell empty cell 4716 empty cell empty cell empty cell empty cell
Install transverse pavement markings All Undefined empty cell empty cell 189 empty cell empty cell empty cell empty cell empty cell empty cell
Install transverse pavement markings Fatal/ Injury Stop empty cell empty cell empty cell empty cell empty cell empty cell empty cell k 57(8)10 empty cell
Install transverse pavement markings Serious Injury Stop empty cell empty cell empty cell empty cell empty cell empty cell empty cell k 84(13)10 empty cell
Install transverse pavement markings Slight Injury Stop empty cell empty cell empty cell empty cell empty cell empty cell empty cell k 52(11)10 empty cell
Install transverse pavement markings All Stop empty cell empty cell empty cell empty cell empty cell empty cell empty cell l 66(8)10 empty cell
Install transverse pavement markings All Stop empty cell empty cell empty cell empty cell empty cell empty cell empty cell k 48(14)10 empty cell
Install transverse pavement markings All Stop empty cell empty cell empty cell empty cell empty cell empty cell empty cell n 45(15)10 empty cell
Install transverse pavement markings All Stop empty cell empty cell empty cell empty cell empty cell empty cell empty cell o 68(11)10 empty cell
Install Stop-Ahead Pavement Markings All Stop Rural empty cell empty cell empty cell -4(30)43 empty cell empty cell empty cell empty cell
Install Stop-Ahead Pavement Markings All Stop Rural empty cell empty cell empty cell empty cell 29(30)43 empty cell empty cell empty cell
Install Stop-Ahead Pavement Markings Injury Stop Rural empty cell 22(20)43 empty cell empty cell empty cell empty cell empty cell empty cell
Install Stop-Ahead Pavement Markings All Stop Rural empty cell 31(10)43 empty cell empty cell empty cell empty cell empty cell empty cell
Install Stop-Ahead Pavement Markings Injury Stop Rural 3-Leg 55(30)43 empty cell empty cell empty cell empty cell empty cell empty cell
Install Stop-Ahead Pavement MarkingsConvert All Stop Rural 3-Leg 60(20)43 empty cell empty cell empty cell empty cell empty cell empty cell
Install Stop-Ahead Pavement Markings Injury Stop Rural 4-Leg 12(30)43 empty cell empty cell empty cell empty cell empty cell empty cell
Install Stop-Ahead Pavement Markings All Stop Rural 4-Leg 23(20)43 empty cell empty cell empty cell empty cell empty cell empty cell
Install Stop-Ahead Pavement Markings Injury Stop (all-way) Rural empty cell 42(30)43 empty cell empty cell empty cell empty cell empty cell empty cell
Install Stop-Ahead Pavement Markings All Stop (all-way) Rural empty cell 56(20)43 empty cell empty cell empty cell empty cell empty cell empty cell
Install Stop-Ahead Pavement Markings Injury Minor Road stop-controlled Rural empty cell 8(30)43 empty cell empty cell empty cell empty cell empty cell empty cell
Install Stop-Ahead Pavement Markings All Minor Road stop-controlled Rural empty cell 13(20)43 empty cell empty cell empty cell empty cell empty cell empty cell
Install transverse rumble strips on approaches All Stop empty cell empty cell 289 empty cell empty cell empty cell empty cell empty cell empty cell
Install transverse rumble strips on approaches All Undefined empty cell empty cell empty cell empty cell empty cell 909 empty cell empty cell empty cell
Install transverse rumble strips on approaches All No Signal Rural empty cell 3516 empty cell empty cell empty cell empty cell empty cell empty cell
Mark pavement with supplementary warning messages All No Signal empty cell empty cell 616 empty cell empty cell empty cell empty cell empty cell empty cell
Mark pavement with supplementary warning messages Stop Urban empty cell empty cell empty cell 30(66)28 empty cell empty cell empty cell empty cell empty cell
Advance Stop bar to leave dedicated space for cyclists All Signal empty cell empty cell empty cell empty cell empty cell empty cell empty cell t 5331 empty cell
Provide bicycle lanes All Undefined empty cell empty cell empty cell empty cell empty cell empty cell empty cell t 3631 empty cell
Resurface pavement All Undefined empty cell empty cell empty cell empty cell empty cell empty cell empty cell p 4716 empty cell
Regulatory
Convert Stop control to Yield control All Stop Urban 4-Leg -127(70)22 empty cell empty cell empty cell empty cell empty cell empty cell
Convert Stop control to Yield control All Stop All empty cell -13711 empty cell empty cell empty cell empty cell empty cell empty cell
Convert to all-way STOP control (from two-way Stop control) Fatal/ Injury Stop Urban empty cell 70(6)43 empty cell empty cell empty cell empty cell empty cell empty cell
Convert to all-way STOP control (from two-way Stop control) All Stop Urban empty cell empty cell 20(52)18 75(3)43 18(10)43 empty cell r 43(20)43 empty cell
Convert to all-way STOP control (from two-way Stop control) All Stop Rural empty cell 48(4)43 empty cell empty cell empty cell empty cell empty cell empty cell
Convert two-way to one-way roadway All Undefined empty cell empty cell 269 empty cell empty cell empty cell empty cell empty cell empty cell
Convert Yield control to Stop control All No Signal empty cell empty cell 2916 empty cell 916 empty cell empty cell empty cell empty cell
Install no left-turn and no u-turn signs All Undefined Urban and Suburban empty cell 70(20)43 77(20)43 empty cell empty cell empty cell empty cell 19,435-42,000 (Total)
Permit right-turn-on-red All Signal empty cell empty cell -7(1)2 empty cell empty cell empty cell empty cell r -43(24)2 empty cell
Permit right-turn-on-red All Signal empty cell empty cell empty cell empty cell empty cell empty cell empty cell rt -69(10)43 empty cell
Permit right-turn-on-red All Signal empty cell empty cell empty cell empty cell empty cell empty cell empty cell r -57(20)43 empty cell
Permit right-turn-on-red All Signal empty cell empty cell empty cell empty cell empty cell empty cell empty cell t -80(20)43 empty cell
Permit right-turn-on-red Fatal/ Injury Signal empty cell empty cell empty cell empty cell empty cell empty cell empty cell j -60(5)6 empty cell
Permit right-turn-on-red PDO Signal empty cell empty cell empty cell empty cell empty cell empty cell empty cell j -10(1)6 empty cell
Prohibit left turns All Undefined empty cell empty cell 459 909 empty cell 309 empty cell r 109 empty cell
Prohibit left-turns with “No Left Turn Sign” All Undefined Urban and Suburban 3-Leg and 4-Leg 68(10)43 64(20)43 empty cell empty cell empty cell empty cell 19,435-42,000
Prohibit right-turn-on-red All Signal empty cell empty cell 341 empty cell 309 209 209 b 309 empty cell
Prohibit turns All Undefined All empty cell empty cell empty cell empty cell empty cell empty cell s 451 empty cell
Restrict parking near intersections to off-street All Undefined empty cell empty cell 4916 empty cell empty cell empty cell empty cell r 309 empty cell
Lighting
Install Lighting All Signal empty cell empty cell 3031 empty cell empty cell empty cell empty cell d 5031 empty cell
Install Lighting Fatal/ Injury Signal empty cell empty cell 1731 empty cell empty cell empty cell empty cell empty cell empty cell
Install Lighting All No Signal empty cell empty cell 4716 empty cell empty cell empty cell empty cell empty cell empty cell
Install Lighting Injury empty cell All empty cell 38(10)43 empty cell empty cell empty cell empty cell empty cell empty cell
Install Lighting Injury empty cell All empty cell empty cell empty cell empty cell empty cell empty cell r 42(20)43 empty cell
Operational
Convert Stop Control (2-way) to signal control All Stop empty cell empty cell 289 empty cell 749 empty cell empty cell empty cell empty cell
Convert Stop Control (2-way) to signal control Injury Stop empty cell empty cell 439 empty cell empty cell empty cell empty cell empty cell empty cell
Convert Stop Control (2-way) to signal control and install left-turn lane All Stop empty cell empty cell 369 empty cell 749 89 empty cell empty cell empty cell
Convert Stop Control (2-way) to signal control and install left-turn lane Injury Stop empty cell empty cell 539 empty cell empty cell empty cell empty cell empty cell empty cell
Increase enforcement related to motorist yielding in marked crosswalks combined with a public education campaign All Undefined empty cell empty cell empty cell empty cell empty cell empty cell empty cell r 2342 empty cell
Install angled median crosswalk All Undefined empty cell empty cell 1216 empty cell empty cell empty cell empty cell empty cell empty cell
Install beacon (flashing) at intersection All Undefined All empty cell 301 empty cell empty cell empty cell empty cell empty cell empty cell
Install cameras to detect red-light running All Signal Urban empty cell empty cell empty cell 26(3)43 -18(3)43 empty cell empty cell empty cell
Install cameras to detect red-light running All Signal empty cell empty cell -12(5)23 empty cell empty cell empty cell empty cell empty cell empty cell
Install cameras to detect red-light running All Signal Urban empty cell empty cell 45(6)36 empty cell empty cell empty cell empty cell empty cell
Install cameras to detect red-light running Fatal/ Injury Signal empty cell empty cell -14(9)23 empty cell empty cell empty cell empty cell empty cell empty cell
Install cameras to detect red-light running Fatal/ Injury Signal empty cell empty cell empty cell empty cell 16(6)27 -24(10)43 empty cell empty cell empty cell
Install flashing red/yellow signal (MUTCD: intersection control beacon) All No Signal empty cell empty cell 259 empty cell 359 empty cell empty cell empty cell empty cell
Install flashing red/yellow signal (MUTCD: intersection control beacon) All No Signal empty cell empty cell 269 empty cell 369 empty cell empty cell empty cell empty cell
Install flashing red/yellow signal (MUTCD: intersection control beacon) All No Signal empty cell empty cell empty cell empty cell empty cell empty cell empty cell a 509 empty cell
Install flashing red/yellow signal (MUTCD: intersection control beacon) Fatal/ Injury No Signal empty cell empty cell 509 empty cell empty cell empty cell empty cell empty cell empty cell
Install pedestrian crossing (signed and marked with curb ramps and extensions) All No Signal empty cell empty cell 3716 empty cell empty cell empty cell empty cell empty cell empty cell
Install pedestrian overpass/underpass All No Signal empty cell empty cell empty cell empty cell empty cell empty cell empty cell r 1316 empty cell
Install stop signs at alternate intersections in residential areas All Stop Urban empty cell 5034 empty cell empty cell empty cell empty cell empty cell empty cell
Install stop signs at alternate intersections in residential areas Fatal/ Injury Stop Urban empty cell 6734 empty cell empty cell empty cell empty cell empty cell empty cell
Note: Any CRF with a reference of 43 is added to this version of the Intersection Safety Issue Brief 8.


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29. Preston, H. and Schoenecker, T., "Bypass Lane Safety, Operations, and Design Study." MN/RC-2000-14, St. Paul, Minnesota Department of Transportation, (1999)

30. Retting, R. A., Chapline, J. F., and Williams, A. F., "Changes in Crash Risk Following Re-timing of Traffic Signal Change Intervals." Accident Analysis and Prevention, Vol. 34, No. 2, Oxford, N.Y., Pergamon Press, (2002) pp. 215-220

31. Rodegerdts, L. A., Nevers, B., and Robinson, B., "Signalized Intersections: Informational Guide." FHWA-HRT-04-091, (2004)

32. Rodegerdts, L. A., Blogg, M., Wemple, E., Myers, E., Kyte, M., Dixon, M., List, G., Flannery, A., Troutbeck, R., Brilon, W., Wu, N., Persaud, B., Lyon, C.,Harkey, D., and Carter, E. C., "Roundabouts in the United States." NCHRP Report 572, Washington, D.C., Transportation Research Board of the National Academies, (2007)

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35. Sayed, T., El Esawey, M., and Pump, J., "Evaluating the Safety Impacts of Improving Signal Visibility at Urban Signalized Intersections." 2007 TRB 86th Annual Meeting: Compendium of Papers CD-ROM, Vol. TRB#07-135, Washington, D.C., (2007)

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38. Xu, L., "Right Turns Followed by U-Turns Versus Direct Left Turns: A Comparison of Safety Issues." ITE Journal, Vol. 71, No. 11, Washington, D.C., Institute of Transportation Engineers, (2001) pp. 36-43

39. Zegeer, C., Stewart, R., Huang, H., and Lagerwey, P., "Safety Effects of Marked vs. Unmarked Crosswalks at Uncontrolled Locations: Executive Summary and Recommended Guidelines," FHWA-RD-01-075, (March 2002)

40. Zimmerman, K. and Bonneson, J., "In-Service Evaluation of the Detection-Control System for Isolated High-Speed Intersections." 2006 TRB 85th Annual Meeting: Compendium of Papers CD-ROM, Vol. TRB#06-1252, Washington, D.C., (2006)

41. Harkey, D., Srinivasan, R., Baek, J., Council, F. M., Eccles, K., Lefler, N., Gross, F., Persaud, B., Lyon, C., Hauer, E., and Bonneson, J. A., "Crash Reduction Factors for Traffic Engineering and ITS Improvements," NCHRP Report No. 617, (2008)

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43. Highway Safety Manual 1st Edition. AASHTO. April 2009 Draft.



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