Rhode Island 2006 Five Percent Report
This report is in response to the Federal requirement that each state describe at least 5 percent of its locations currently exhibiting the most severe highway safety needs, in accordance with Sections 148(c)(1)(D) and 148(g)(3)(A), of Title 23, United States Code. Each state’s report is to include potential remedies to the hazardous locations identified; estimated costs of the remedies; and impediments to implementation of the remedies other than costs. The reports included on this Web site represent a variety of methods utilized and various degrees of road coverage. Therefore, this report cannot be compared with the other reports included on this Web site.
Protection from Discovery and Admission into Evidence—Under 23 U.S.C. 148(g)(4) information collected or compiled for any purpose directly relating to this report shall not be subject to discovery or admitted into evidence in a Federal or State court proceeding or considered for other purposes in any action for damages arising from any occurrence at a location identified or addressed in the reports. |
Additional information, including the specific legislative requirements, can be found in the guidance provided by the Federal Highway Administration,
http://safety.fhwa.dot.gov/safetealu/fiveguidance.htm.
4.0 – Rhode Island’s "5 Percent" Report
This section of the HSIP report is to identify locations in Rhode Island exhibiting the most severe safety needs in the state. Rhode Island’s hazard elimination safety improvement program has traditionally focused on intersections, and as such RIDOT has elected to focus this section of the report on the safety needs of intersections. It should be noted that RIDOT understands that crashes are also occurring along corridors and potentially at mid-block intersections and intends to incorporate these locations into future HSIP submittals.
4.1 – Methodology for Identifying the Top 5% of the State’s Intersections
RIDOT evaluated a number of alternatives in developing the "5 Percent" report, which included a review of the frequency of all crashes, frequency of only severe and fatal crashes, the development of an equivalent property damage only (EPDO) crash ranking, the development of severe and fatal crash rates for intersections and corridors, and the potential for using a combination of these approaches. However, due to limitations with available data at the time this report was developed, Rhode Island used crash frequency as the means to identify the intersections exhibiting the most severe safety needs. The following is an overview of the process used.
The first step was for RIDOT staff to identify all of the intersections throughout the state using a Geographic Information System (GIS). The DOT has a base map that has each intersection labeled with a unique identifier. Staff was then able to link the accident databases for 2003 through 2005 with the intersection layer and assign each of the approximately 150,000 individual crashes to the roadway network. Crashes that occurred along two intersecting links within the GIS were then grouped and assigned to the corresponding intersection. Crashes that occurred outside of the two intersecting links were considered crashes occurring along a corridor and were eliminated from further consideration.
Once the crashes were assigned to intersections, each record then had its corresponding injury (crash severity) code linked. This allowed staff to identify not only the intersections having the greatest frequency of crashes, but also the ability to rank the intersections exhibiting a high frequency of severe injury and fatal crashes. In addition, by knowing the severity of the crash, a cost for each injury type was then assigned.
For the purposes of this report, RIDOT elected to value a property damage only (PDO) crash at $2,300, each type of injury (no visible injury (complaint), bruising, and bleeding and broken bones) at $63,000, and a fatal injury at $3,000,000. These values are the same as those used in evaluating high hazard locations in the HSIP program.
Since crash occurrences are random in nature, RIDOT first reviewed the data for the crashes at intersections and identified that a significant percentage were a single property damage only crash that occurred once over the three-year period. To ensure that only the intersections exhibiting the most severe safety needs are identified, it was decided that locations having on average 5 or more crashes a year (15 or more over the three year period) would be considered. The 5 crashes per year threshold was selected because this is typically the minimum number of crashes required before an engineering review of an intersection is initiated.
Once the intersections having 15 or more crashes were identified, they were then ranked by their resulting severity cost. By assigning a cost to an intersection’s total crash history over the three year period, it ensured that the less severe crashes did not over represent the more severe. The top five percent of these intersections, which resulted in 50 intersections, have been tentatively identified as locations exhibiting the most severe safety needs. The following sections provide an overview of the results and identify these 50 locations.
4.2 – State’s Top 5% of Intersections Exhibiting Greatest Need
During the 2003 through 2005 reporting period, Rhode Island experienced approximately 150,300 crashes. Of these crashes, a total of 125,293 were able to be mapped to the road network and used in the analysis. Using the methodology described in Section 4.1 above for locating crashes at intersections, 47 percent (58,786) of the crashes were determined to have occurred at or within the influence area of an intersection or interchange. The remaining 53 percent of the crashes were considered to have occurred along segments or corridors. Figure 4.1 depicts the crash severity at Rhode Island’s intersections and along its corridors and Table 4.1 shows the resulting estimated costs of these crashes over the time period.
Figure 4.1 – Total Crashes by Severity 2003-2005
Table 4.1 – Estimated Cost of Crashes 2003-2005
|
Severity |
Intersection |
Corridor |
Total |
No Injury |
$127,132,500 |
$133,639,200 |
$260,771,700 |
Complaint |
$655,578,000 |
$620,911,000 |
$1,276,489,000 |
Bruise |
$126,819,000 |
$155,106,000 |
$281,925,000 |
Bleeding |
$93,240,000 |
$139,608,000 |
$232,848,000 |
Fatal |
$255,000,000 |
$540,000,000 |
$795,000,000 |
|
Total |
$1,257,769,500 |
$1,324,101,600 |
$2,847,333,700 |
4.2.1 – Intersection Results
Slightly more than 10,600 intersections experienced at least one crash over the three-year period. The majority of the crashes at intersections/interchanges were non-injury related crashes and many of which experienced only one crash over the three-year period. To reduce the effects of random crashes, intersections having 15 or more crashes per year were considered for further review. By placing the crash threshold at 15 or more, this reduced the number of intersections requiring additional review from 10,645 to 908.
The 908 locations accounted for 29,159 crashes or almost half of all the intersection crashes in the state. The distribution of injuries is represented in Figure 4.2 which shows that non-injury crashes were the most prominent. The crashes occurring at these locations were estimated to have a total cost of $588,366,300, which is 47 percent of the cost of all intersection crashes.
Figure 4.2 – Intersections having 15 or More Crashes 2003-2005
From the 908 intersections ranked by cost, the top five percent having the greatest crash cost were identified. This five percent resulted in 45 locations, but for this report the Top 50 intersections having the greatest cost have been selected as exhibiting the greatest need. These 50 locations, identified in Table 4.2, account for 7 percent of all intersection crashes in the state and 14 percent of the crashes occurring at intersections having 15 or more per year. Figure 4.3 shows the distribution of crash severity at these 50 locations.
Table 4.2 – Top 50 Intersections Exhibiting Greatest Needs
|
CITY |
INTERSECTION/INTERCHANGE |
TOTAL ESTIMATED CRASH COST |
STATUS |
|
|
Primary Street |
Secondary Street |
|||
Providence |
I 95 |
Exit 20 (I 195) |
$5,654,900 |
Construction |
Providence |
Broadway |
Service RD |
$5,515,500 |
|
Warwick |
RI 2 (Bald Hill RD) |
RI 113 (EAST AV) |
$5,407,000 |
Design |
Cranston |
RI 2 (Reservoir AV) |
RI 10 (Huntington EW) |
$4,823,400 |
Design |
Providence |
I 95 |
EXIT 22 (US 6 - RI 10) |
$4,348,600 |
|
Cranston |
RI 2 (New London AV) |
RI 5 (Oaklawn AV) |
$4,345,600 |
Design |
Warwick |
RI 5 (Greenwich AV) |
RI 113 (East AV) |
$4,341,900 |
Construction |
Providence |
Union AV |
Webster AV |
$4,242,100 |
City Signal |
Warwick |
US 1 (Post RD) |
Veterans Memorial DR |
$4,149,200 |
|
Warwick |
Jefferson BL |
Jefferson Park RD |
$3,992,900 |
City Signal |
Cranston |
I 95 |
RI 10 |
$3,936,300 |
|
Providence |
US 1 (N Main ST) |
RI 126 (Smithfield AV) |
$3,885,700 |
|
South Kingstown |
RI 108 (Kingston RD) |
Main ST |
$3,849,400 |
|
Middletown |
RI 138 (E Main RD) |
RI 138 A (Aquidneck AV) |
$3,702,700 |
Construction |
Providence |
Eddy ST |
Public ST |
$3,689,800 |
City Signal |
Cranston |
RI 14 (Plainfield PK) |
Plainfield CI |
$3,632,800 |
Design |
Cranston |
RI 2 (Reservoir AV) |
Garden City DR |
$3,630,500 |
Design |
Cranston |
RI 12 (Scituate AV) |
RI 51 (Phenix AV) |
$3,623,600 |
Design |
North Kingstown |
US 1 (Tower Hill RD) |
Shermantown RD |
$3,606,100 |
Construction |
Warwick |
US 1 (Post RD) |
RI 37 |
$3,590,700 |
Design |
East Providence |
RI 103 (Pawtucket AV) |
Veterans Memorial PW |
$3,566,100 |
|
Cranston |
RI 2 (Reservoir AV) |
Norfolk ST |
$3,554,600 |
|
Middletown |
RI 114 (W Main RD) |
Rogers LN |
$3,552,300 |
Construction |
Providence |
US 1 (Elmwood AV) |
Mc Kinley ST |
$3,536,200 |
Design |
Burrillville |
RI 7 (Douglas PK) |
RI 102 (Bronco HW) |
$3,487,000 |
Design |
Coventry |
RI 3 (Tiogue AV) |
Pilgrim AV |
$3,475,500 |
|
Pawtucket |
Central AV |
Cottage ST |
$3,463,100 |
City Signal |
Providence |
Gallup ST |
Prairie AV |
$3,417,100 |
City Signal |
Johnston |
RI 5 (Atawood AV) |
Central AV |
$3,367,900 |
Construction |
Pawtucket |
East ST |
Roosevelt AV |
$3,358,700 |
City Signal |
Warren |
RI 136 (Metacom AV) |
Seymour ST |
$3,304,900 |
Design |
Warwick |
I 95 |
EXIT 10 (RI 117) |
$3,291,300 |
Construction |
Westerly |
RI 1 A (Beach ST) |
Elm ST |
$3,288,800 |
Design |
Exeter |
RI 2 (S County TL) |
Main ST |
$3,286,500 |
|
Warwick |
RI 117 A (Warwick AV) |
Oakland Beach AV |
$3,244,200 |
Design |
Cumberland |
RI 122 (Mendon RD) |
RI 99 |
$3,204,200 |
Design |
Providence |
US 1 (Elmwood AV) |
Roger Williams AV |
$2,934,400 |
Design |
Providence |
US 6 |
RI 10 |
$2,873,700 |
Design |
North Smithfield |
RI 146 (Eddie Dowling HW) |
Sayles Hill RD |
$2,721,500 |
Design |
Providence |
I 95 |
EXIT 18 (Thurbers AV) |
$2,550,000 |
|
Providence |
US 1 (Elmwood AV) |
Potters AV |
$2,284,600 |
Design |
Cranston |
RI 2 (Reservoir AV) |
RI 12 (Park AV) |
$2,216,600 |
Design |
Cranston |
RI 2 (New London AV) |
Sockanosset Cross RD |
$2,121,400 |
|
Warwick |
RI 2 (Bald Hill RD) |
RI 115 (Toll Gate RD) |
$2,114,500 |
|
Cranston |
US 1 (Elmwood AV) |
RI 12 (Park AV) |
$2,047,800 |
Design |
Providence |
I 95 |
EXIT 24 (Branch AV) |
$2,012,400 |
Design |
Providence |
RI 10 (Huntington EW) |
Union AV |
$2,007,800 |
Construction |
Providence |
Eddy ST |
Thurbers AV |
$1,905,700 |
Construction |
Pawtucket |
I 95 |
EXIT 29 (Cottage ST) |
$1,883,600 |
|
South Kingstown |
US 1 (Tower Hill RD) |
RI 138 (Bridgetown RD) |
$1,862,500 |
Construction |
Total Costs |
$169,903,600 |
|||
Figure 4.3 – Distribution of Crash Severity at the Top 50 Intersections
4.3 – Potential Remedies and Costs for Locations Identified
As Table 4.2 shows, more than 70 percent of the 50 intersections have already been scheduled for improvements. Twenty of the intersections/interchanges are currently in design, 10 are under construction, and 6 are city controlled signals. The remaining 24 locations will require further evaluation. RIDOT has not conducted an in-depth analysis of these locations to ascertain the cause of the crashes or what the actual collision countermeasures could be implemented. However, since these locations are intersections and interchanges, some basic countermeasures may take the form of:
- Installation of traffic signals at unsignalized locations,
- Upgrade, modify, or remove traffic signal or adjust signal timing/phasings,
- Construct/improve channelization; add turn lanes,
- Prohibition of certain turn maneuvers,
- Install signing and restriping,
- Improve sight distance,
- Provide traffic signal preemption for emergency vehicles,
- Extension of acceleration and deceleration lanes on interstate ramps,
- Reconstruction of interchange.
The above list of countermeasures is not meant to be an exhaustive list, but it is to show a range of potential measures that could be implemented. An engineering analysis should be conducted to identify the appropriate countermeasures for each location. Based on that analysis, an estimated cost can then be developed for each intersection/interchange.
