R U M B L E S T R I P S By Gary Dirlam, Mn/DOT District 3 Traffic Engineer

Last year 657 people died on Minnesota Highways

Mn/DOT Lost one of its own to a Head- On Crash

PennDOT conducted rumble strip research on two lane rural road highways. R O A D R E S E A R C H

PennDOT has adopted Centerline Rumble Strips as part of its 3R program estimating a 20% reduction in fatal crashes. R O A D R E S E A R C H

82 % drift off road drivers were drowsy/asleep 53% drift off road right/ 47% drift off road left Micro-sleeps of 4-5 seconds, vehicle can travel 300 feet Micro-sleepeyes stay open, brain not processing information Michigan Study R O A D R E S E A R C H

Multi-state review (7 states) 98 sites with 211 miles Insurance Institute for Highway Safety R O A D R E S E A R C H

AADT range from 5,000 to 22,000 Average ADT of 8,800 to 9,700 after Overall 14% reduction in all crashes Insurance Institute for Highway Safety R O A D R E S E A R C H

25% reduction in injury head-on and side-wipe crashes Only Minn. showed increase in opposing direction injury crashes Minn. increase was not statistically significant Insurance Institute for Highway Safety R O A D R E S E A R C H

Maine is the only other state I know which has used the RS each side of Centerline Washington State and Oregon have included a widen center median to install the Rumble Strip Design of Centerline Rumble Strips R O A D R E S E A R C H

Experimental application of centerline rumble strips –Milled-in a center median –In no passing zones Tactile vibration if driver encroaches centerline Installed 2 years ago Oregon Solution R O A D R E S E A R C H

Next steps: –wait for one more year of data –develop regression models –apply comparison group and empirical-bayes approach Data would indicate the rumble strips have been effective at reducing target crashes Oregon: Conclusions after 2 years R O A D R E S E A R C H

Design of Centerline Rumble Strips California, Pennsylvania,and Colorado have used the Rumble Strips across the Centerline Minnesota Metro has used Rumble Strips across Centerline as has Districts 6, 3 and 8 on Highway 23 R O A D R E S E A R C H

Design of Centerline Rumble Strips District 3 has used the separated Rumble Strips for the 8 miles installed on Highway 55 and 4 miles on Highway 169 in 2000 District 3 has used the separated Rumble Strips for the 190 miles installed October 2003 R O A D R E S E A R C H

Where Installed? R O A D R E S E A R C H Each section of the 190 miles of new rumble strip had one fatal crash in last 10 years Evaluate performance over this winter Plan for second CLRS project

Minnesota Research Research driver interaction with centerline rumble strips and design of centerline RL Research mid-lane rumble strip Mid-lane could replace centerline and shoulder rumble strip R O A D R E S E A R C H

Rumble Strips in District 3 I N S T A L L A T I O N

Sweeps up debris I N S T A L L A T I O N

Challenge to Materials Engineers Safety problem is too great to ignore and/or accept 5 fatal crashes each year in District 3 Materials Engineers challenge is to develop treatment for RS to preserve pavement life and life of pavement markings T H E F U T U R E

Challenge to Materials Engineers District 3 recently installed shoulder RS on Highway 12 which were fog sealed Fog seal also fogged the epoxy edge line District 4 masked over center line tape with protective covering and removed covering after paver passed over T H E F U T U R E

Challenge to Materials Engineers Next day, fog seal of macro surface covered up tape pavement markings $2.12 /ft material investment covered (tape was 5 years old) So far I have not heard of any contractor paying for ruining pavement markings T H E F U T U R E

Questions or Comments Q&AQ&A

Building More. Building Faster. Moving Better.