Evaluation of the Safety Edge

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General Information
Study Number: TPF-5(097)
Lead Organization: Federal Highway Administration
Solicitation Number: 872
Partners: CA, CO, GADOT, IN, MS, NC, NY, UT
Status: Closed
Est. Completion Date:
Contract/Other Number:
Last Updated: Feb 02, 2012
Contract End Date:
Financial Summary
Contract Amount: $225,000.00
Total Commitments Received: $360,000.00
100% SP&R Approval: Approved
Contact Information
Lead Study Contact(s): Carol Tan
carol.tan@fhwa.dot.gov
Phone: 202-493-3315
FHWA Technical Liaison(s): Carol Tan
carol.tan@fhwa.dot.gov
Phone: 202-493-3315
Organization Year Commitments Technical Contact Name Funding Contact Name Contact Number Email Address
California Department of Transportation 2004 $15,000.00 Craig Copelan Osama Elhamshary Osama_Elhamshary@dot.ca.gov
California Department of Transportation 2005 $15,000.00 Craig Copelan Osama Elhamshary Osama_Elhamshary@dot.ca.gov
California Department of Transportation 2006 $15,000.00 Craig Copelan Osama Elhamshary Osama_Elhamshary@dot.ca.gov
Colorado Department of Transportation 2006 $15,000.00 Skip Outcalt Aziz Khan aziz.khan@state.co.us
Colorado Department of Transportation 2007 $15,000.00 Skip Outcalt Aziz Khan aziz.khan@state.co.us
Colorado Department of Transportation 2008 $15,000.00 Skip Outcalt Aziz Khan aziz.khan@state.co.us
Georgia Department of Transportation 2004 $15,000.00 Stanley Kim Supriya Kamatkar 404-347-0552 skamatkar@dot.ga.gov
Georgia Department of Transportation 2005 $15,000.00 Stanley Kim Supriya Kamatkar 404-347-0552 skamatkar@dot.ga.gov
Georgia Department of Transportation 2006 $15,000.00 Stanley Kim Supriya Kamatkar 404-347-0552 skamatkar@dot.ga.gov
Indiana Department of Transportation 2004 $15,000.00 Todd Shields Tommy Nantung 765-463-1521 ext 248 tnantung@indot.in.gov
Indiana Department of Transportation 2005 $15,000.00 Todd Shields Tommy Nantung 765-463-1521 ext 248 tnantung@indot.in.gov
Indiana Department of Transportation 2006 $15,000.00 Todd Shields Tommy Nantung 765-463-1521 ext 248 tnantung@indot.in.gov
Mississippi Department of Transportation 2005 $15,000.00 James Watkins James Watkins 601-359-7650 jwatkins@mdot.state.ms.us
Mississippi Department of Transportation 2006 $15,000.00 James Watkins James Watkins 601-359-7650 jwatkins@mdot.state.ms.us
Mississippi Department of Transportation 2007 $15,000.00 James Watkins James Watkins 601-359-7650 jwatkins@mdot.state.ms.us
New York State Department of Transportation 2004 $15,000.00 Dave Clements Gary Frederick 518-457-4645 gary.frederick@dot.ny.gov
New York State Department of Transportation 2005 $15,000.00 Dave Clements Gary Frederick 518-457-4645 gary.frederick@dot.ny.gov
New York State Department of Transportation 2006 $15,000.00 Dave Clements Gary Frederick 518-457-4645 gary.frederick@dot.ny.gov
North Carolina Department of Transportation 2004 $15,000.00 Emily McGraw Rodger Rochelle 919-715-4657 rdrochelle@dot.state.nc.us
North Carolina Department of Transportation 2005 $15,000.00 Emily McGraw Rodger Rochelle 919-715-4657 rdrochelle@dot.state.nc.us
North Carolina Department of Transportation 2006 $15,000.00 Emily McGraw Rodger Rochelle 919-715-4657 rdrochelle@dot.state.nc.us
Utah Department of Transportation 2005 $15,000.00 Mack Christensen Daniel Hsiao 801-386-4929 dhsiao@utah.gov
Utah Department of Transportation 2006 $15,000.00 Mack Christensen Daniel Hsiao 801-386-4929 dhsiao@utah.gov
Utah Department of Transportation 2007 $15,000.00 Mack Christensen Daniel Hsiao 801-386-4929 dhsiao@utah.gov

Study Description

It is known that pavement edge (vertical) drop-offs, ranging in height from two inches to five inches, are frequently observed at the pavement edge on two-lane rural roadways. When an errant vehicle leaves the edge of the traveled path and encounters a pavement edge drop-off, it may be difficult for the driver to negotiate the drop-off and safely return to the traveled way. There is potential for the tire to scrape along the drop-off instead of being able to negotiate safely back into the traveled way. This unexpected tire engagement and corresponding resistance often leads to driver over-correction, directing the vehicle to return to the roadway at a sharper angle than necessary. On narrow two-lane roadways, this can result in the vehicle encroaching into the opposite lane of traffic and being involved in a secondary collision. This secondary collision can take the form of a (1) head-on collision with the opposing lane traffic, (2) sideswipe collision with the opposing lane traffic, (3) a run-off-road crash on the opposite side of the road, or (4) an overturn either within the traveled way or on the opposite side of the roadway.

One pavement edge solution being used by some states, particularly when a pavement overlay is applied, is the termination of the pavement edge at a sloped angle, creating a fillet rather than a vertical edge. Prior research tends to indicate that the edge fillet, currently termed the "safety edge" or "edge wedge," presents less resistance to vehicle tires and can lead to a smoother, more controlled reentry back into the traveled way. Further evaluation is needed on the safety edge to determine its effectiveness.

Objectives

The goal of the proposed research is to evaluate the effectiveness of using the Safety Edge (edge wedge) to help prevent and reduce severity of pavement edge drop-off related crashes. A before-after evaluation (Empirical Bayes method) will be performed on sites with upcoming installations of the safety edge in the U.S.

Scope of Work

The initial scope of the Safety Edge Pooled Funds Study is to conduct a research project totaling $500,000 over three years. The end results will be an Empirical Bayes evaluation, using before-after data (where safety edges are installed), to help determine their effectiveness in reducing the number and severity of crashes due to pavement edge drop-offs. A contractor will be hired to collect before data (crash, traffic and roadway) this early summer (2004) at each of the sites where states believe they will be installing the safety edge. Once installation is complete, data will be collected and used to help determine the effectiveness in reducing crash frequency and severity. This construction season at least eight states are planning to install safety edges; it is our intent to collect data from each of these states, where appropriate sites and data are available. FHWA is spending $150,000 of FY 04 safety research funds to help begin the collection of data due to the rapid timeframe.

Comments

Funding commitments will continue to be accepted through August 31, 2004. States interested in joining the study should contact Ms. Lisa Williams at (202) 493-3375.

This project is open to any number of participating states, with a minimum of 5 states. The approximate amount of funding requested per state is $15,000 per year for 3 years. Total anticipated state funds are $225,000 over 3 years. FHWA will contribute $275,000.

12/4/09: Status Update - Year 3 dropoff, traffic and crash data were added to the project database and analysis of the combined data began. The analysis results will be reported in the final report in April 2010.

Subjects: Safety and Human Performance

Documents Attached
Title File/Link Type Privacy Download
Draft Final Report 110495-01R_Year_3_Draft_Final_Report.pdf Final Report Public
Year 3 - Final Report 110495-01R_Year_3_Final_Report.pdf Final Report Public
Year 3 - Final Report 110495-01R-Year-3-Final-Report.pdf Final Report Public
Meeting Minutes from First Conference Call, 2/2/05 call_notes_02-02-05.pdf Other Public
Details and Scanned Provisions from Georgia and Indiana - 1 superelevated.pdf Other Public
Details and Scanned Provisions from Georgia and Indiana - 2 contract_rs-27756.pdf Other Public
Details and Scanned Provisions from Georgia and Indiana - 3 project_csstp_m003_00_179.pdf Other Public
Details and Scanned Provisions from Georgia and Indiana - 4 edge_wedge_detail.pdf Other Public
Details and Scanned Provisions from Georgia and Indiana - 5 special_provision_01-05-2005.pdf Other Public
Sections 4.3-4 and Tasks sections_4-3-4_and_tasks.pdf Other Public
Quarterly Report 1 FY 2005 qtr1_2005.pdf Quarterly Progress Report Public
Quarterly Report 2 FY 2005 qtr2_2005.pdf Quarterly Progress Report Public
Quarterly Report 3 FY 2005 qrtrly_rpt_3_2005.pdf Quarterly Progress Report Public
Quarterly Report 4 FY 2005 qrtrly_rpt_4_2005.pdf Quarterly Progress Report Public
Quarterly Report 1 FY 2006 qrtrly_rpt_1_2006.pdf Quarterly Progress Report Public
Year 1 - Interim Report 110495-01R_Interim_Report.pdf Report Public
Safety Edge Evaluation safety_edge_summary.pdf Study Summary Public
Safety Edge Final Work Plan final_work_plan.pdf Work Plan Public

Evaluation of the Safety Edge

General Information
Study Number: TPF-5(097)
Lead Organization: Federal Highway Administration
Solicitation Number: 872
Partners: CA, CO, GADOT, IN, MS, NC, NY, UT
Status: Closed
Est. Completion Date:
Contract/Other Number:
Last Updated: Feb 02, 2012
Contract End Date:
Financial Summary
Contract Amount: $225,000.00
Total Commitments Received: $360,000.00
100% SP&R Approval:
Contact Information
Lead Study Contact(s): Carol Tan
carol.tan@fhwa.dot.gov
Phone: 202-493-3315
FHWA Technical Liaison(s): Carol Tan
carol.tan@fhwa.dot.gov
Phone: 202-493-3315
Commitments by Organizations
Organization Year Commitments Technical Contact Name Funding Contact Name Contact Number Email Address
California Department of Transportation 2004 $15,000.00 Craig Copelan Osama Elhamshary Osama_Elhamshary@dot.ca.gov
California Department of Transportation 2005 $15,000.00 Craig Copelan Osama Elhamshary Osama_Elhamshary@dot.ca.gov
California Department of Transportation 2006 $15,000.00 Craig Copelan Osama Elhamshary Osama_Elhamshary@dot.ca.gov
Colorado Department of Transportation 2006 $15,000.00 Skip Outcalt Aziz Khan aziz.khan@state.co.us
Colorado Department of Transportation 2007 $15,000.00 Skip Outcalt Aziz Khan aziz.khan@state.co.us
Colorado Department of Transportation 2008 $15,000.00 Skip Outcalt Aziz Khan aziz.khan@state.co.us
Georgia Department of Transportation 2004 $15,000.00 Stanley Kim Supriya Kamatkar 404-347-0552 skamatkar@dot.ga.gov
Georgia Department of Transportation 2005 $15,000.00 Stanley Kim Supriya Kamatkar 404-347-0552 skamatkar@dot.ga.gov
Georgia Department of Transportation 2006 $15,000.00 Stanley Kim Supriya Kamatkar 404-347-0552 skamatkar@dot.ga.gov
Indiana Department of Transportation 2004 $15,000.00 Todd Shields Tommy Nantung 765-463-1521 ext 248 tnantung@indot.in.gov
Indiana Department of Transportation 2005 $15,000.00 Todd Shields Tommy Nantung 765-463-1521 ext 248 tnantung@indot.in.gov
Indiana Department of Transportation 2006 $15,000.00 Todd Shields Tommy Nantung 765-463-1521 ext 248 tnantung@indot.in.gov
Mississippi Department of Transportation 2005 $15,000.00 James Watkins James Watkins 601-359-7650 jwatkins@mdot.state.ms.us
Mississippi Department of Transportation 2006 $15,000.00 James Watkins James Watkins 601-359-7650 jwatkins@mdot.state.ms.us
Mississippi Department of Transportation 2007 $15,000.00 James Watkins James Watkins 601-359-7650 jwatkins@mdot.state.ms.us
New York State Department of Transportation 2004 $15,000.00 Dave Clements Gary Frederick 518-457-4645 gary.frederick@dot.ny.gov
New York State Department of Transportation 2005 $15,000.00 Dave Clements Gary Frederick 518-457-4645 gary.frederick@dot.ny.gov
New York State Department of Transportation 2006 $15,000.00 Dave Clements Gary Frederick 518-457-4645 gary.frederick@dot.ny.gov
North Carolina Department of Transportation 2004 $15,000.00 Emily McGraw Rodger Rochelle 919-715-4657 rdrochelle@dot.state.nc.us
North Carolina Department of Transportation 2005 $15,000.00 Emily McGraw Rodger Rochelle 919-715-4657 rdrochelle@dot.state.nc.us
North Carolina Department of Transportation 2006 $15,000.00 Emily McGraw Rodger Rochelle 919-715-4657 rdrochelle@dot.state.nc.us
Utah Department of Transportation 2005 $15,000.00 Mack Christensen Daniel Hsiao 801-386-4929 dhsiao@utah.gov
Utah Department of Transportation 2006 $15,000.00 Mack Christensen Daniel Hsiao 801-386-4929 dhsiao@utah.gov
Utah Department of Transportation 2007 $15,000.00 Mack Christensen Daniel Hsiao 801-386-4929 dhsiao@utah.gov

Study Description

Study Description

It is known that pavement edge (vertical) drop-offs, ranging in height from two inches to five inches, are frequently observed at the pavement edge on two-lane rural roadways. When an errant vehicle leaves the edge of the traveled path and encounters a pavement edge drop-off, it may be difficult for the driver to negotiate the drop-off and safely return to the traveled way. There is potential for the tire to scrape along the drop-off instead of being able to negotiate safely back into the traveled way. This unexpected tire engagement and corresponding resistance often leads to driver over-correction, directing the vehicle to return to the roadway at a sharper angle than necessary. On narrow two-lane roadways, this can result in the vehicle encroaching into the opposite lane of traffic and being involved in a secondary collision. This secondary collision can take the form of a (1) head-on collision with the opposing lane traffic, (2) sideswipe collision with the opposing lane traffic, (3) a run-off-road crash on the opposite side of the road, or (4) an overturn either within the traveled way or on the opposite side of the roadway.

One pavement edge solution being used by some states, particularly when a pavement overlay is applied, is the termination of the pavement edge at a sloped angle, creating a fillet rather than a vertical edge. Prior research tends to indicate that the edge fillet, currently termed the "safety edge" or "edge wedge," presents less resistance to vehicle tires and can lead to a smoother, more controlled reentry back into the traveled way. Further evaluation is needed on the safety edge to determine its effectiveness.

Objectives

The goal of the proposed research is to evaluate the effectiveness of using the Safety Edge (edge wedge) to help prevent and reduce severity of pavement edge drop-off related crashes. A before-after evaluation (Empirical Bayes method) will be performed on sites with upcoming installations of the safety edge in the U.S.

Scope of Work

The initial scope of the Safety Edge Pooled Funds Study is to conduct a research project totaling $500,000 over three years. The end results will be an Empirical Bayes evaluation, using before-after data (where safety edges are installed), to help determine their effectiveness in reducing the number and severity of crashes due to pavement edge drop-offs. A contractor will be hired to collect before data (crash, traffic and roadway) this early summer (2004) at each of the sites where states believe they will be installing the safety edge. Once installation is complete, data will be collected and used to help determine the effectiveness in reducing crash frequency and severity. This construction season at least eight states are planning to install safety edges; it is our intent to collect data from each of these states, where appropriate sites and data are available. FHWA is spending $150,000 of FY 04 safety research funds to help begin the collection of data due to the rapid timeframe.

Comments

Funding commitments will continue to be accepted through August 31, 2004. States interested in joining the study should contact Ms. Lisa Williams at (202) 493-3375.

This project is open to any number of participating states, with a minimum of 5 states. The approximate amount of funding requested per state is $15,000 per year for 3 years. Total anticipated state funds are $225,000 over 3 years. FHWA will contribute $275,000.

12/4/09: Status Update - Year 3 dropoff, traffic and crash data were added to the project database and analysis of the combined data began. The analysis results will be reported in the final report in April 2010.

Subjects: Safety and Human Performance

Title File/Link Type Private
Draft Final Report 110495-01R_Year_3_Draft_Final_Report.pdf Final Report Public
Year 3 - Final Report 110495-01R_Year_3_Final_Report.pdf Final Report Public
Year 3 - Final Report 110495-01R-Year-3-Final-Report.pdf Final Report Public
Meeting Minutes from First Conference Call, 2/2/05 call_notes_02-02-05.pdf Other Public
Details and Scanned Provisions from Georgia and Indiana - 1 superelevated.pdf Other Public
Details and Scanned Provisions from Georgia and Indiana - 2 contract_rs-27756.pdf Other Public
Details and Scanned Provisions from Georgia and Indiana - 3 project_csstp_m003_00_179.pdf Other Public
Details and Scanned Provisions from Georgia and Indiana - 4 edge_wedge_detail.pdf Other Public
Details and Scanned Provisions from Georgia and Indiana - 5 special_provision_01-05-2005.pdf Other Public
Sections 4.3-4 and Tasks sections_4-3-4_and_tasks.pdf Other Public
Quarterly Report 1 FY 2005 qtr1_2005.pdf Quarterly Progress Report Public
Quarterly Report 2 FY 2005 qtr2_2005.pdf Quarterly Progress Report Public
Quarterly Report 3 FY 2005 qrtrly_rpt_3_2005.pdf Quarterly Progress Report Public
Quarterly Report 4 FY 2005 qrtrly_rpt_4_2005.pdf Quarterly Progress Report Public
Quarterly Report 1 FY 2006 qrtrly_rpt_1_2006.pdf Quarterly Progress Report Public
Year 1 - Interim Report 110495-01R_Interim_Report.pdf Report Public
Safety Edge Evaluation safety_edge_summary.pdf Study Summary Public
Safety Edge Final Work Plan final_work_plan.pdf Work Plan Public

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