Wisconsin 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.
2006 Highway Safety Improvement Program Reports
Wisconsin Department of Transportation
August 2006
5% Report
Background
Given the aggressive timeframe established to develop this report, Wisconsin chose to utilize an existing Safety Management System. Due to the complicated nature and sensitivity of this endeavor, a data-driven methodology was implemented which applied a “standardized” approach for producing the report. The methodology may be subject to change for future efforts.
Geographic Extent of the Analysis
- State Trunk routes only
- Local routes have not been included due to a current inability to “place” crashes at appropriate locations along the network
- An experimental project which implements a new strategy to address this process is nearing completion
- Wisconsin plans to incorporate Local routes into the 5% analysis by August, 2008
- The initial incorporation of this information could include fewer than 5 years of crash data
Methodology
The Wisconsin Meta-Manager Safety Information System consists of a 3-part “Systems-level” analysis. Initially, every mile of the State Trunk Highway System is placed into one of ten functional “peer” groups so that baseline crash statistics (e.g. mean, standard deviation, etc.) can be generated for “like” roadways.
“Like-Highway” Peer Groups |
|
1 = Rural and Small Urban Freeways. |
6 = Rural STN ADT less than 750. |
2 = Rural and Small Urban Expressways. |
7 = Large Urban Freeways. |
3 = Rural STN ADT greater than 3500 ADT. |
8 = Large Urban Divided Highways and One Way. |
4 = Rural STN ADT between 2000 and 3500 ADT. |
9 = Large Urban Undivided Highways. |
5 = Rural STN ADT between 750 and 2000 ADT |
10 = Small Urban STN. |
The total number of crashes is tabulated as are the number of severe injury/death crashes (AK), Run-off-the-road crashes (ROR) and Intersection crashes (INT) for each segment of the system. A proportion of AK, ROR and INT crashes to Total crashes is then produced.
- ...the State Trunk System is divided into roughly 20,000 segments for this analysis
- ...deer crashes are removed from the data prior to processing
- ...utilizes 5 years of crash data
The Crash Rate is generated using the following equation:
Segment-wide crash total for the appropriate years (e.g. 5) * 100,000,000 (VMT)
AADT 1 * Length of segment * appropriate years (e.g. 5) * 365
Secondly, indicator flags are determined for the crash types occurring on each segment. A “Crash Rate Flag” is signaled positive when the number of crashes is significantly above the average for the “peer” group (i.e. greater than or equal to 1 Standard deviation). Similarly, the “AK Flag”, “ROR Flag” and “INT Flag” are signaled positive when the proportion of those crashes is significantly above the average for the “peer” group.
- The 5% analysis selects segments which “flag” for both Crash Rate and AK proportion and experience a minimum of 3 crashes per year over the analysis period (5 years).
- “Crash Rate” is incorporated into the selection criteria so that the potential for “randomness” of AK crashes is filtered out (i.e. the site must have an overall crash problem)
- AK proportions are highest on rural roads (i.e. less ADT, fewer overall crashes)
- These segments are then sorted by the proportion of AK crashes so that the “worst” 5% can be identified for the report
- The two sites with the greatest AK proportion are selected from each of the 10 “peer” groups
- Additionally, any site which experiences 1.5 AK crashes per year or greater is added to the selection group
- Ultimately, this approach results in the identification of 30 “sites of promise”
- Remedies consist of both “Intersection” as well as Non-Intersection modifications
- Estimated costs are not included for 2006 but will be for 2007
- For 2007, the collaborative effort utilized to arrive at a list of sites will include an estimation of Scope and an estimation of Cost
One of the challenges of producing this report is the “time lag” which exists between the filing of a crash report and the availability of that crash and it’s location attributes in the WisDOT database. Once the initial list was produced, a statewide oversight group assisted with the exclusion of sites which were included erroneously.
Many of the sites identified by this effort are in the existing Improvement Program or Corridor Studies. To view the sites, please refer to Attachment 1 (Table 3).
Implementation
Development of the site list and accompanying estimates will facilitate the introduction of these “project” locations into the Improvement Program scoping process as potential HSIP-funded projects (for those which are not already included). Since driver behavior is a significant contributing factor in Death/Serious Injury crashes, multi-disciplinary solutions are appropriate. It is understood that future HSIP programs will not be limited to this list.
Please list the following “initial point of contact” information on the USDOT web site:
Brad Javenkoski
608-264-8725
bradley.javenkoski@dot.state.wi.us
| ROUTE | Near_or_At | COUNTY | TREATMENT |
|---|---|---|---|
| 012E | CTH O | JUNEAU | Modify Non-Intersection |
| 012E | CTH D | DANE | Modify Intersection |
| 012W | Gammon Rd | DANE | Modify Intersection |
| 016E | Main St | JEFFERSON | Modify Intersection |
| 051N | IH 39 | DANE | Modify Non-Intersection |
| 081E | CTH T | ROCK | Modify Intersection |
| 090E | STH 58 | JUNEAU | Modify Non-Intersection |
| 151N | OFF RAMP TO CTH M | DODGE | Modify Intersection |
| 031N | STH 50 WB | KENOSHA | Modify Non-Intersection |
| 032N | 50TH ST | KENOSHA | Modify Non-Intersection |
| 032N | STH X794 WB | MILWAUKEE | Modify Intersection |
| 038N | CTH G | RACINE | Modify Intersection |
| 038N | W MAPLE ST | MILWAUKEE | Modify Non-Intersection |
| 045N | CTH H | WASHINGTON | Modify Intersection |
| 045N | STH 33 | WASHINGTON | Modify Intersection |
| 045N | CTH MM | MILWAUKEE | Modify Non-Intersection |
| 045N | W GRANGE AVE | MILWAUKEE | Modify Non-Intersection |
| 050E | CTH H | KENOSHA | Modify Intersection |
| 050E | 30TH AVE | KENOSHA | Modify Intersection |
| 100N | CTH EE | MILWAUKEE | Modify Non-Intersection |
| 158E | STH 31 NB | KENOSHA | Modify Non-Intersection |
| 158E | 22ND AVE (CTH Y EXT) | KENOSHA | Modify Non-Intersection |
| 010W | CTH AP | WINNEBAGO | Modify Non-Intersection |
| 041N | STH 21 | WINNEBAGO | Modify Intersection |
| 057S | CTH PP | SHEBOYGAN | Modify Intersection |
| 067N | HOLZMAN RD | SHEBOYGAN | Modify Non-Intersection |
| 023E | CTH M | MARQUETTE | Modify Intersection |
| 039N | STH 54 | PORTAGE | Modify Intersection |
| 008E | CTH O | BARRON | Modify Intersection |
| 053N | CTH B | WASHBURN | Modify Intersection |
