Prioritizing Safety in the Transportation Improvement Program

Original publication: SHSP Implementation Process Model, Supplement Number 1 – Case Studies; FHWA-SA-10-025; 2010(PDF, 1MB)

Key Accomplishments

• Increased use of safety as a factor in prioritizing TIP projects.
• Achieved better understanding of safety problems through data analysis in MPO areas.
• Increased number of local safety projects proposed.

While safety is required in transportation planning and is frequently stated as a planning goal, often safety issues are not given sufficient weight in the project selection process to ensure safety projects are advanced into the programming phase. To increase the number of safety projects programmed, several Michigan metropolitan planning organizations (MPO) have developed prioritization processes that explicitly consider safety.

MPO project prioritization often takes the form of weighting project factors using a point system. Incorporating safety into the weighting process can be achieved through allocating a certain number of points to safety, which may vary depending on whether a project is categorized as capacity, preservation, or non-motorized. For example, one MPO allocated up to 20 points out of a possible 100 to safety-related factors for preservation projects and 20 points out of 125 points for capacity projects. Safety factors considered included separation of non-motorized modes from vehicles, crash rates, and whether a project includes countermeasures such as signs and striping to reduce crashes and severity.

The Michigan Office of Highway Safety Planning funds a consultant to analyze safety data and identify hazardous locations in most of the MPO planning areas. As part of the project prioritization process, several MPOs consider whether a project addresses a hazardous location included in the safety analysis.

Results

Through the SHSP process, awareness of the Michigan safety goal among MPOs has increased. The number of requests for local safety funds has increased, as well as the funding available for such projects.

Contact:
Marsha Small
Manager, Statewide Transportation Planning
Michigan DOT
517-373-9054
smallm@michigan.gov

Michigan DOT Uses MOU to Define Roles Among Data Generators

Original publication: SHSP Implementation Process Model, Supplement Number 1 – Case Studies; FHWA-SA-10-025; 2010(PDF, 1MB)

Key Accomplishments

• Developed an MOU to clearly define roles, responsibilities, and funding obligations related to crash data management.
• Improved data quality and timeliness.
• Ensured consistent use of data Statewide through uniform data queries.

The Michigan DOT (MDOT), Department of State, and State Police signed a memorandum of understanding (MOU) defining crash data management and funding. The State agencies invested in a team of three people, including a dedicated project manager, over a five-year period. The MOU provided a basis for ongoing cooperation and communication concerning Michigan’s data systems. Researchers can review current data without personal identifiers within 24 hours of receiving crash reports. The Michigan Office of Highway Safety Planning (OHSP) provides funding for a research center at Wayne State University, which provides public access to annual reports on safety data.

The State’s safety stakeholders understand they all need to be working with the same data and statistics for each crash type; therefore, a uniform data query was developed for Statewide use to ensure consistency in the number of crashes for each emphasis area and other crash types.

Michigan currently is transitioning to electronic crash reporting and citation management to reduce reporting errors. Paper crash reports have an average of 1.5 errors per form, while the error rate for electronic crash reports is very low given the quality checks that can be implemented (e.g., it is impossible to enter conflicting data such as the weather was sunny and the crash occurred at midnight). The OHSP contributed $1 million in funding in 2007 for electronic crash reporting equipment. One county currently operates a completely paperless system. Citation information is processed quickly; therefore, in areas with electronic data processes, a person can drive directly to the courthouse to pay the fine after receiving a citation.

Results

The State established a uniform crash reporting system with improved data quality, reliability, and timeliness. Data are now widely available to all potential users to improve safety data analysis and dissemination.

Contact:
Dale Lighthizer
Supervising Engineer
Michigan DOT
517-373-2334
lighthizerd@michigan.gov

SHSP Committee Provides Forum for Data Collection Improvements

Original publication: SHSP Implementation Process Model, Supplement Number 1 – Case Studies; FHWA-SA-10-025; 2010(PDF, 1MB)

Key Accomplishments

• Used collaborative process of the TRCC to conduct problem solving related to data quality.
• Improved quality of commercial vehicle safety data resulting in the receipt of MCSAP funding.
• Implemented improvements in one of the key SHSP emphasis areas.

Since data is the foundation of transportation safety planning, the Ohio Department of Transportation identified data improvement as one of the priority emphasis areas in its SHSP. Each year the Federal Motor Carrier Safety Administration (FMCSA) publishes a State-by-State safety data quality rating that summarizes the completeness, timeliness, accuracy, and consistency of State-reported commercial motor vehicle crash and inspection records. States receive either a poor, a fair, or a good rating. Ohio received a “fair” rating and wanted to improve its “timeliness” rating to receive Motor Carrier Safety Assistance Program (MCSAP) incentive funds.

Ohio’s TRCC is responsible for overseeing data improvements included in the SHSP. The TRCC is the perfect forum for addressing this issue since all the necessary partners are members of the committee. Ohio’s Department of Public Safety (DPS), which provides motor carrier crash data to the FMCSA, did not realize that by not meeting the Federal data reporting deadline, the State was being penalized. Through its participation in Traffic Records Coordinating Committee (TRCC) meetings, DPS learned of this problem and was able to modify its data reporting process to accommodate the deadline. The policy changes involved the department obtaining crash data from local governments in a timelier manner to meet FMCSAs data reporting requirements.

Results

By improving the timeliness of its data reporting, and therefore its safety data quality rating, Ohio received several hundred thousand dollars in MCSAP incentive funds.

Contact:
Tom Hollingsworth
Chief, Traffic Statistics
Ohio Department of Public Safety
614-387-2800
THollingsworth@dps.state.oh.us

Safety Warrants and Spot Safety Index

Original publication: HSIP Noteworthy Practice Series, HSIP Project Identification; FHWA-SA-11-02; 2011(PDF, 2.7MB)

The North Carolina Department of Transportation (NCDOT) started to identify shortcomings in its problem identification method in the mid-1990s. The previous method focused on identifying locations with a potential safety issue based on factors such as crash frequency, crash rate, and crash severity. In many cases, the locations identified did not exhibit a correctable crash type and were congestion related issues. For example, NCDOT repeatedly identified signalized intersections exhibiting a high frequency of rear-end collisions, but attributed the collisions to congestion and driver inattention rather than a roadway factor.

Intersection Warrants:

I-1: Frontal Impact

I-2: Last Year Increase

I-3: Frequency with Severity Index Min

I-4: Night Location without Streetlight

I-5: Chronic Pattern

Section Warrants:

S-1: Run Off Road- Wet Conditions

S-2: Run Off Road

S-3: Wet Road Conditions

S-4: Non-Intersection Night Location without Streetlight

Bridge Warrant:

B-1: Bridge

Bike/Ped Intersection Warrants:

P-1: Last 3 Years (pedestrians)

P-2: Darkness with Streetlights

P-3: Alcohol Involvement

P-4: Chronic Location

X-1: Last 3 years (bicyclists)

X-2: Darkness with Streetlights

X-3: Alcohol Involvement

X-4: Chronic Location

Beginning with the 1996 HSIP, a set of safety warrants was established for intersections and roadway segments to target locations exhibiting a pattern of correctable crash types or conditions, as well as locations with a significant increase in crash frequency during the past calendar year. NCDOT has continued to expand and modify the safety warrants throughout the years to improve the identification process.

NCDOT initially screens the network (including local roads) for potential safety improvement locations using four categories of safety warrants: intersections, sections, bridges, and bicycle and pedestrian intersections. The safety warrants are analyzed annually using 5 to 10 years of crash data by querying the crash database. The current warrant criteria are based on crash frequency, severity, conditions, and percentage of target crashes. When a location meets the warrant criteria, it is flagged. As an example, an interstate segment would be flagged based on run-off road crashes if a minimum of 30 total crashes occurred on the segment, the crash rate is greater than 60 crashes per mile, and a minimum of 60 percent of the total crashes were run off the road. After a location is flagged, a weighting factor is calculated based on the warrant criteria. The weighting factors are summed for locations meeting multiple warrants and are used to rank locations to determine which will receive priority for further analysis and investigation by the corresponding Regional Traffic Engineering and Highway Division staff. The Regional Traffic Engineers are responsible for identifying potential countermeasures and developing projects.

All safety projects are submitted to North Carolina’s Safety Oversight Committee, which was established to help select projects to receive Spot Safety Program funding. To provide clear and consistent data-driven selection process, the Spot Safety Index (SSI) was developed as a decision support tool to perform an initial prioritization of all candidate projects from across the state. It ensures safety investments are focused on locations with the greatest need and potential for improvement. The SSI is calculated based on a 100-point scale and is composed of four parts: Safety Factor (60 points), Constructability (5 points – e.g., ROW acquisition needs), Department Goals (5 points) and Division/Region Priority (30 points). The Safety Factor is based on the benefit-cost ratio, Severity Index, and whether the project is identified in the HSIP List or identified through a Road Safety Audit (RSA). An initial list of prioritized projects is developed by ranking projects based on the SSI. However, the Committee must take other considerations into account to develop the final list, including distribution of funding to the 14 districts and the effectiveness of countermeasures identified in the projects based on results from the state’s evaluation group.

Key Accomplishments

• Developed network screening method to identify locations with severe and correctable crash patterns.
• Continued to update network screening process to improve the identification of relevant safety issues and locations.
• Developed systematic project prioritization ranking method that considers benefit-cost analysis, departmental and regional priorities, and ease of constructability.

Results

The development of the safety warrants for use in the network screening process has enabled NCDOT to focus their analysis on the identification of locations with severe crashes and crash patterns correctable by infrastructure safety countermeasures. NCDOT also has successfully established a clear and consistent data-driven process for selecting and prioritizing projects for funding.

Contact

Stephen Lowry
Safety Improvement Engineer
North Carolina Department of Transportation
919-773-2892
slowry@ncdot.gov

Statewide and Regional SHSP Coalitions

Original publication: HSIP Noteworthy Practice Series, SHSP Stakeholder Involvement; FHWA-SA-11-02; 2011(PDF, 2.6MB)

In November 2004, Missouri’s SHSP, titled Blueprint for Safer Roadways, was developed in consultation with many safety advocates, including engineers, law enforcement, educators, and emergency responders. Prior to the Blueprint, Missouri never had a statewide safety goal. The Blueprint established the fatality reduction goal of 1,000 or fewer fatalities by 2008.

One of the key principles guiding development of the 2004 Blueprint was deploying targeted strategies at both the state and regional level. The document outlined a strategy to organize 10 regional safety coalitions designed to work in concert with the Missouri Coalition for Roadway Safety (MCRS). As soon as the Blueprint was published, champions pushed very hard to sell the goal and promote shared responsibility through individual meetings within each region. Presentations promoted the “Essential Eight” strategies Missouri must implement to make significant progress in reaching the projected goal. The Champions helped establish regional coalitions and provided the coalitions with safety planning toolkits, including data packages, copies of the Blueprint, and copies of the National Cooperative Research Program (NCHRP) 500 Series.

Before the Blueprint, no forum existed for regional multidisciplinary discussions on safety. Purpose and procedural guidelines now document the organizational structure and activities of the MCRS and Regional Coalitions. The 10 regional coalitions are charged to:

• Assist with the implementation of the Blueprint;
• Conduct regional data analysis to guide highway safety activities;
• Expand regional safety network and partnerships;
• Actively participate in MCRS meetings, campaigns, and promotions;
• Develop a localized safety plan for the region; and
• Facilitate the expenditure of allocated funds.

Participation in the coalitions is open to any national, state, regional, or local organization and any individual. The MCRS includes an Executive Committee with representatives from over a dozen agencies and organizations, and is presided over by a chair and vice chair. Nine subcommittees were also established to effectively address the mission of the Coalition on a statewide level, including: Commercial Motor Vehicle, Elder Mobility and Safety, Enforcement, Impaired Driving, Infrastructure, Legislative, Public Information, Strategic Planning and Implementation, and Traffic Records Coordinating.

In each regional coalition, the corresponding Missouri Department of Transportation (MoDOT) district office and Missouri State Highway Patrol troop help facilitate meetings, expand coalition membership, develop and implement regional strategic highway safety plans, and distribute funding. In addition, MoDOT trained a representative from each district to provide data analysis support to each regional coalition.

Two-million dollars of state road funds are offered each year to support regional safety plans activities. Annual grant applications are submitted to MoDOT for enforcement and education programs supporting Blueprint priorities. Previously, such programs had been supported exclusively through Federal Section 402 funds with project selection by the MoDOT Highway Safety Office. Regional safety plans developed by local stakeholders can provide more targeted programs. MoDOT also utilizes district safety funds to support regional engineering projects.

The MCRS meets quarterly, including an Executive Committee meeting and discussion with regional coalition contacts before an afternoon meeting with the broader statewide coalition. Every other year the MCRS holds a Blueprint Conference and uses state funds to bring up to 10 representatives from each regional coalition. The conferences combine presentations with participatory working groups. Statewide and regional coalition members played an active role in the 2008 update, Blueprint to Arrive Alive, which, among other changes, expanded the original “Essential Eight” to the “Targeted Ten” strategies to improve safety. The Blueprint appendices include data for each coalition, which are updated annually. MCRS also sends out a weekly e-mail with updated statewide and regional fatality counts. All of the above activities are designed to keep safety on the forefront and to maintain regular communication and collaboration among safety stakeholders.

Key Accomplishments

• Established collaborative, multidisciplinary, regional partnerships pursuing common safety goals.
• Funded localized safety programs addressing Blueprint priorities via 10 annual regional safety plans.

Results

Together, the MCRS and Regional Coalitions have embraced the elements of the Blueprint and implemented a comprehensive, coordinated, and focused effort to reduce fatalities and disabling injuries on Missouri roads. Missouri’s original fatality reduction goal of 1,000 or fewer fatalities by 2008 was met one year early. Regional Coalitions have expanded their number of partners and regional safety plans include a wider variety of localized safety programs.

Contact

Leanna Depue, Ph.D.
Highway Safety Director
Missouri Department of Transportation
573-751-7643
leanna.depue@modot.mo.gov

Grant Writing Assistance Focuses on SHSP

Original publication: SHSP Implementation Process Model, Supplement Number 1 – Case Studies; FHWA-SA-10-025; 2010(PDF, 1MB)

Key Accomplishments

• Developed efficient grant application process.
• Used current, centralized data rather than local data.
• Strengthened the partnership between the Highway Safety Office and law enforcement.

The Michigan Office of Highway Safety Planning (OHSP) partners with police on traffic enforcement efforts as part of its annual Highway Safety Plan (HSP). To receive funding, each year every county law enforcement agency and the State Police write grant applications describing the data-driven need for traffic enforcement efforts. Law enforcement agencies typically have few grant writing resources, and in the past it took considerable time to revise grant application drafts by both law enforcement and OHSP staff. To assist law enforcement with this process, the OHSP developed a law enforcement grant shell, or template, to provide a framework for applications.

The OHSP populates the template with current crash data on key SHSP emphasis areas, including safety belts and impaired driving. The grant shell describes general enforcement strategies to support the SHSP, including national mobilization efforts defined by NHTSA and strategies based on State problem identification. The grant application does not dictate methods for enforcement so each agency can customize approaches for its region, but it provides consistency on addressing SHSP goals related to law enforcement.

Results

This approach has allowed law enforcement to minimize time writing grant applications and improved the quality of the applications.

Contact:
Mike Prince
Director
Michigan Office of Highway Safety Planning
517-333-5301
princem@michigan.gov

Utah Flexes HSIP Funds to Enhance Partners' Safety Efforts

Original publication: HSIP Noteworthy Practice Series, Use of the HSIP Flexible Funding Provision; FHWA-SA-11-02; 2011(PDF, 2.8MB)

Overall, the Utah Department of Transportation (UDOT) spends about $20 million per year on roadway safety, one-half of which is funded via a state funding mechanism and one-half via the Highway Safety Improvement Program (HSIP). The State receives about $4 million per year in Federal highway safety grant funding (i.e., Sections 402, 405, 408, 410, etc.). According to crash data, the majority of fatal and serious injury crashes in Utah are behavior related. However, the state funding mechanism is limited to infrastructure investments. Given the level of behavior related crashes, UDOT decided to take full advantage of the HSIP flexibility provision to fund noninfrastructure safety programs. “There is a lot of talk about an integrated approach to safety – the 4Es (enforcement, education, engineering, and emergency response). We are utilizing the flex funds to address the other Es beyond engineering,” said Utah Director of Traffic and Safety Robert Hull.

UDOT has flexed approximately 10 percent of its HSIP funds each year for an annual investment of approximately $900,000 in safety funds for noninfrastructure programs between FY 2006 and FY 2009. This has enabled UDOT to support its overall safety program – Zero Fatalities – and reinforce partnerships with new and existing safety partners through support of their programs. Partners include the Department of Public Safety (DPS); Highway Safety Office (HSO); Utah Department of Health (DOH) Violence and Injury Prevention Program; Utah Safety Council (USC); and Utah Attorney General’s Office. Programs were identified by the partner agencies and then reviewed by UDOT as potential HSIP flex projects, considering their link to the Utah’s Comprehensive Safety Plan (the State’s strategic highway safety plan).

UDOT used flex funds for informational safety and public outreach materials as well as to support the implementation of a multidisciplinary safety summit. One of the projects identified by DPS and DOH was a teen memoriam yearbook, which includes stories from families about teens that have died in crashes. Funding from UDOT pays for the creative development and production while the DOH and DPS work with the families to develop the stories. The book has been used in teen driver education classes for the past two years.

Additional education and outreach programs supported by flex funds include the Operation Lifesaver program to reduce pedestrian crashes at rail crossings and support for USC’s Alive@25 program that promotes safe driving among youth. The 14 Safe Kids chapters across the State receive funding to buy car and booster seats that are given away during Safe Kids Week.

UDOT also contributes flex funds to support a Traffic Safety Resource Prosecutor position. This attorney, who is housed in the Attorney General’s office, works with county and city prosecuting attorneys to help them handle impaired driving-related court cases. The resource prosecutor provides quarterly reports of their activities to ensure objectives of the program are met.

“Applying for flex funds is not difficult given that all the data needed is assembled in other annual reports, including those on the HSIP program, railroad program, Safe Routes to School, and the 5% Report,” said Hull.

Key Accomplishments

• Strengthened relationships in the safety community through funding partner programs.
• Enabled improved creativity in addressing safety issues.
• Demonstrated greater levels of success through collaboration.

Results

Since 2000 Utah has experienced a reduction in fatal crashes of 34 percent. In 2009, fatalities were the lowest in 34 years. Overall, flex funding has been used to strengthen the Zero Fatalities Program, the overarching safety effort in Utah. Since Zero Fatalities was initiated in 2005, all of the safety campaigns in the State have been branded with the logo. The last market survey in 2009 showed that Utah residents had a 75 percent awareness rate of the Zero Fatalities campaign and the related safety programs. In addition, the flex funded Traffic Safety Prosecutor has helped cities and counties without experience in impaired driving-related court cases reduce the number of dismissals or reduced charges.

Contact

Robert Hull
Director, Traffic and Safety Division
Utah DOT
801-965-4273
rhull@utah.gov

Teen Driver Study Commission Adopts SHSP Strategies and Advances Legislation

Original publication: SHSP Implementation Process Model, Supplement Number 1 – Case Studies; FHWA-SA-10-025; 2010(PDF, 1MB)

Key Accomplishments

• Enhanced communication and coordination among the private and public sectors and State legislators.
• Expedited the implementation of SHSP strategies by partnering with a public-private commission in the young driver emphasis area.
• Drafted legislation to strengthen the GDL law, require safety belt use in rear seats, and eliminate plea bargaining for GDL licensed drivers.

Despite a strong Graduated Driver Licensing (GDL) law, New Jersey experienced a continued high volume of teen crashes. As a result, leadership identified young driver crashes as an SHSP emphasis area. The SHSP Young Driver Emphasis Area Team developed three primary strategies and 10 action steps to reduce crashes among this population.

Concurrently New Jersey enacted a law establishing a Teen Driver Study Commission. The 15 member Commission is comprised of representatives of both the public and private sector as well as members of the State legislature. The charge of the Commission is to assess teen driving within New Jersey and recommend ways to reduce fatal and injury crashes. The Commission incorporated all of the young driver emphasis area strategies into their 47 recommendations. These are grouped into seven areas: Graduated Driver License, driver education, driver training, enforcement/judicial, insurance industry, schools, and technology. Recommendations requiring legislative action were presented to the Highway Traffic Safety Policy Advisory Council and the legislature.

Results

The leaders of the SHSP effort successfully partnered with the Teen Driver Study Commission and achieved agreement to move the SHSP strategies forward through the Commission. Although agencies receiving public funds are prohibited from lobbying, the private sector members of the Commission have been able to successfully champion bills included in the Commission’s recommended policy initiatives.

Contact:
Pam Fischer
Director, Division of Highway Traffic Safety
New Jersey Department of Law and Public Safety
609-633-9272
Pam.Fischer@lps.state.nj.us

MPO Safety Management Planning

Original publication: HSIP Noteworthy Practice Series, SHSP Stakeholder Involvement; FHWA-SA-11-02; 2011(PDF, 2.6MB)

In 2008, the Cheyenne Metropolitan Planning Organization (MPO) completed its first Transportation Safety Management Plan (TSMP), an MPO level plan akin to statewide SHSPs. The MPO has successfully engaged partners in developing and implementing the TSMP through a combination of activities.

As part of plan development, the MPO convened the first safety summit in the region, involving 60 stakeholders from multiple disciplines. The TSMP defined six emphasis areas requiring focus in the region: impaired driving, occupant protection, distracted driving, older drivers, younger drivers, and intersections. The plan also identified strategies in each area.

Following completion of the TSMP, the MPO developed grant applications seeking funding from the Wyoming Highway Safety Office (HSO) for two safety strategies: a summit for law enforcement personnel to increase enforcement of the secondary occupant protection statute, and development of an intersection safety analysis. These efforts maintained engagement of the law enforcement community in preparation for the summit and the engineering community as they completed the safety study. The MPO submitted a second round of grant applications to the HSO for FY 2010. Activities proposed included a briefing of state legislators on safety issues and a Battle of the Belts competition to increase safety belt use among teens.

In the fall of 2009, the MPO convened meetings of all six emphasis area teams, inviting individuals who had participated in the summit as well as new stakeholders. Each team reviewed the strategies in the TSMP, identified new ideas, and discussed implementation of the two planned efforts for FY 2010. The MPO convened a second set of team meetings in the spring of 2010. The teams developed action plans that are updated on an ongoing basis. HSO staff frequently attend events and are represented on most of the emphasis area teams.

The legislative briefing addressed issues from three of the emphasis areas and engaged a number of stakeholders in its planning. Specifically, the briefing addressed a primary safety belt law, alternative transportation to reduce DUI, and a medical advisory board. Organization of the briefing resulted in engaging a new safety stakeholder, the Wyoming Seatbelt Coalition, which helped the group frame the case for a primary safety belt law at the legislative summit. The MPO has been invited to serve as a member of the coalition, ensuring ongoing communication about the issue. A private sector company in favor of a safety belt law was engaged for the legislative briefing to present the economic benefits of increasing safety belt use through passing a primary safety belt law and demonstrate support for such a change. The American Association of Retired Persons (AARP) served as a speaker given their support of the Medical Advisory Board proposal. A public safety officer from the Casper Police Department, which started a successful alternative transportation program, also served as a speaker and became engaged in sharing information with the Cheyenne Police Department on how to start such a program.

A second effort undertaken in the community in May 2010 was Battle of the Belts, a campaign to increase the rates of safety belt use in high schools. Each school held a contest to increase safety belt use and the winning school received a cash prize. Planning this event engaged members of the younger driver and occupant protection teams. The students on the Mayor’s Youth Council became highly involved in event planning and promotion of the competition at their schools. The project allowed the MPO to develop a strong relationship with the principals of the three high schools in town. The Wyoming Safety Council became involved by delivering Alive@25 assemblies at the schools to kickoff the program. Community businesses donated prizes that were distributed to students during the week of the event to reward those students wearing safety belts. The Mayor and Police Chief presented the award to the winning school demonstrating their support of these efforts and helping to continue to build a culture of safety in Cheyenne.

Plans for FY 2011 involve developing a year-round alternative transportation program. This effort will involve the Cheyenne Regional Medical Center’s Injury Prevention Program and the Cheyenne Police Department, which is in the initial stages of configuring an alternative transportation program in Cheyenne.

Moving forward, the MPO is developing grant applications for safety projects to be conducted in FY 2012 based on ideas developed by the emphasis area teams. Smaller-scale safety efforts are also implemented on an ongoing basis, such as developing a fact sheet for law enforcement on the importance of issuing citations for violations by older drivers instead of warnings to ensure an accurate driving record is captured.

Key Accomplishments

• Engaged safety stakeholders in six emphasis areas, a law enforcement summit, a legislative briefing, and other projects.
• Implemented four major safety projects in under two years with help from new stakeholders.

Results

In Cheyenne, safety stakeholder engagement has been built and sustained through MPO leadership – identifying and funding safety projects and working with partners on project implementation. Based on the needs of each project, new safety stakeholders become engaged in the process. Stakeholder interest is sustained when partners have been involved hands-on in implementing a project and see the results. Safety belt use among high school students increased by 10 to 15 percent at each of the schools with the Battle of the Belts Program. An eight-fold increase in citations for nonuse of safety belts followed the safety belt law enforcement summit.

Contact

Sreyoshi Chakraborty
Transportation Planner
Cheyenne MPO
307-638-4384
schakraborty@cheyennecity.org

Level of Service of Safety and Diagnostic Analysis

Original publication: HSIP Noteworthy Practice Series, HSIP Project Identification; FHWA-SA-11-02; 2011(PDF, 2.7MB)

The Colorado Department of Transportation (CDOT) uses two methods for identifying locations with potential for safety improvement: Level of Service of Safety (LOSS) and Diagnostic Analysis. LOSS is based on the concept of Safety Performance Functions (SPF), while Diagnostic Analysis is developed around the idea of statistical pattern recognition.

Design engineers at CDOT pioneered development of the LOSS concept to quantify the magnitude of the safety problem. A crash rate implies a linear relationship between safety and exposure. While crash rates are commonly used to measure safety, they are often misleading since rates change with Annual Average Daily Traffic (AADT). To capture how this rate change takes place, CDOT engineers began calibrating SPFs in the late 1990s based on the work of Dr. Ezra Hauer. By 2001, CDOT had calibrated SPFs for all public roadways in Colorado, which were stratified by the number of lanes, terrain, environment, and functional classification. In 2009, in collaboration with consultants, CDOT developed SPFs for all intersection types.

Development of SPFs supports the conceptual formulation of the LOSS concept. It uses qualitative measures to characterize the safety of a roadway segment in reference to its expected performance. If the number of crashes predicted by the SPF represents normal or expected crash frequency at a specific level of AADT, then the degree of deviation from the norm can be stratified to represent specific levels of safety. To describe road safety from the frequency and severity standpoint, two different SPFs were calibrated: one for the total number of crashes and the other for injury and fatal crashes. When the magnitude of the safety problem is assessed, it is described from the frequency and severity standpoint. The figure (Kononov and Allery, 2003) illustrates the LOSS concept using an SPF calibrated for total crashes expected on the 6-lane urban freeways. The delineated boundary line is located 1.5 standard deviations from the mean, reflecting a Negative Binomial error structure. Four LOSS categories were introduced:

• LOSS-I - Indicates low potential for crash reduction;
• LOSS-II - Indicates low to moderate potential for crash reduction;
• LOSS-III - Indicates moderate to high potential for crash reduction; and
• LOSS-IV - Indicates high potential for crash reduction.

LOSS reflects how the roadway segment is performing in regard to its expected crash frequency and severity at a specific level of AADT. However, it only describes the magnitude of the safety problem; it does not provide any information related to the nature of the problem itself. To investigate the nature of the problem, Colorado uses Direct Diagnostics and Pattern Recognition techniques.

A comprehensive methodology was developed to conduct diagnostic analyses of safety problems. The Direct Diagnostics and Pattern Recognition methods calculate a cumulative binomial probability of the crash types and related characteristics to identify overrepresented elements in the crash data (e.g., dark conditions, overturning vehicles) that may be related to abnormal crash patterns and crash causation. Direct Diagnostics is used for intersection analysis, and Pattern Recognition is used for roadway segments.

CDOT initially used the combination of LOSS and Direct Diagnostics and Pattern Recognition to identify sites with potential for safety improvement only on safety motivated projects. Beginning in 2001, they are applied to all projects at CDOT, including resurfacing, reconstruction, realignment, widening, Environmental Assessments (EA) and Environmental Impact Statements (EIS). CDOT conducts a statewide analysis using Direct Diagnostics and Pattern Recognition and recalibrates SPFs about every five years.

Key Accomplishments

• Calibrated SPFs for all highways.
• Developed sophisticated predictive and diagnostic tools to maximize crash reduction in the state within budget constraints.
• Institutionalized use of these tools throughout the state of Colorado.
• Achieved unprecedented fatal crash reduction of 36 percent over the seven years of sustained application of these advanced methods on all infrastructure and behavioral projects at CDOT.
• Provided substantive conceptual and analytical input for the development of the Highway Safety Manual (HSM).

Results

CDOT developed sophisticated predictive and diagnostic tools to maximize potential crash reduction in the state within constraints of available budgets and institutionalized use of these tools throughout the state of Colorado. Over the seven years of application of the advanced methods on all infrastructure and behavioral projects at CDOT, the state has achieved an unprecedented fatal crash reduction of 36 percent, without reduction in travel or increase in safety expenditures. Additionally, these efforts provided substantive analytical and conceptual input for development of the Highway Safety Manual.

Contact

Bryan Allery
Colorado Department of Transportation
303-757-9967
bryan.allery@dot.state.co.us

Jake Kononov
Colorado Department of Transportation
303-757-9973
jake.kononov@dot.state.co.us