Low Cost Safety Improvements Pooled Fund Study Combination Centerline and Edgeline Rumble Strips Dr. Frank Gross, VHB

Overview u Background u Missouri’s Program u Status of Data Collection u Remaining Data Needs u Evaluation Considerations

Background u Singe-vehicle ROR Crashes l 39 percent of all fatal crashes (FARS, 1999) u Included in Several NCHRP 500 Series Guidebooks l Run Off Road, Head-on, Heavy Trucks, and Horizontal Curves u Run-Off Road Guidebook l 3 Experimental Strategies Edge line “profile marking” Edge line rumble strips Modified shoulder rumble strips (narrow or no paved shoulder) l Ranked 1 st in Phase I Low cost and short implementation timeframe (< 1 year)

Background u Head-on Guidebook l Install centerline rumble strips Tried strategy l Ranked 3 rd in Phase II Low cost Short implementation timeframe (< 1 year) u Heavy Trucks and Horizontal Curve Guides l Shoulder and centerline rumble strips Low to moderate costs Short to medium implementation timeframe (1-2 years) l Heavy-vehicle drivers and horizontal curves

Background u Dual Application l Combination of centerline and edge line rumble strips l Not included in NCHRP 500 Series l Identified by Technical Advisory Committee u NCHRP Survey Results l Approximately 200 miles l 9 States AZ, ID, KY, MO, OR, TX, UT, WA, WY

Missouri DOT Program u Missouri DOT: Better Roads Brighter Future l Improve 85 percent of major route system in 5 years u Part of Program – Install Dual Rumble Strips l Two predominant roadway types 4-lane divided expressways 2-lane roadways. l Includes both rumble strips and stripes Mostly stripes Stripes are placed on the edge line l Posted speed limits mph

Missouri DOT Program u Proposed Strategy Sites for FY l 1170 miles (170 sites for 2007) l 543 miles (75 sites for 2008) l 2351 miles (329 sites for ) u Additional Improvements l Surface improvements (overlay) l Shoulder improvements (upgrade to 4’ where possible) l Others (sign upgrades where necessary)

Status of Data Collection u Missouri l Planned installations Those for SFY 2007 have begun l MO DOT provided roadway/traffic data 2002 – 2005 l MO DOT provided crash database 1997 – 2005

Remaining Data Needs u MO Reference Sites l Sites planned for treatment in later years u Additional States l Proactive evaluation l States planning to install combination rumble strips

Evaluation of Dual Application u Crash Based Evaluation in MO l Proactive before/after evaluation l Evaluate sample of installations l Disaggregate analysis Roadway type Night and weather conditions

Evaluation Considerations u Disaggregate analysis l Functional class l Night and weather conditions u Including other states in evaluation l 4 States are Technical Advisory Committee Members