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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 it’s own to a Head-On Crash. R O A D R E S E A R C H. PennDOT conducted rumble strip research on two lane rural road highways.
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R U M B L E S T R IP S By Gary Dirlam, Mn/DOT District 3 Traffic Engineer
R O A D R E S E A R C H 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.
Michigan Study 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-sleep—eyes stay open, brain not processing information
Insurance Institute for Highway Safety 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
Design of Centerline Rumble Strips 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
Oregon Solution 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: Conclusions after 2 years 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
Design of Centerline Rumble Strips R O A D R E S E A R C H • 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
Design of Centerline Rumble Strips R O A D R E S E A R C H • 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
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 R O A D R E S E A R C H • 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
I N S T A L L A T I O N Rumble Stripsin District 3
Sweeps up debris I N S T A L L A T I O N
Challenge to Materials Engineers T H E F U T U R E • 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
Challenge to Materials Engineers T H E F U T U R E • 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
Challenge to Materials Engineers T H E F U T U R E • 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