Road Safety Audits

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Road Safety Audits

• The Mn/DOT District 2
• Experience

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• Road Safety Audit (RSA)
• US 2 and CSAH 75 Intersection

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What is a road safety audit?

• A formal safety performance examination of an
  existing or future road or intersection by an
  independent audit team.
• safety check-up

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Benefits

• Improve Safety
• Promote safe design practices
• Low cost improvements
• Proactive
• Multimodal

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Team

• Multidisciplinary and Independent
• Road Safety Audit Team
• Seven Mn/DOT experts
• FHWA engineer
• DPS safety expert
• SEH traffic engineer

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US 2 and CSAH 75

• Concerns
• Leech Lake Tribal College
• Top 50 District Ranking

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Data Review

• Initial Meeting
• Intersection Geometry and Traffic Control
• 4-lane expressway intersecting 2-lane road
• 65 mph speed limit on TH 2 and 55 mph speed limit
  on CSAH 75
• Turn lanes on TH 2
• Wide median crossover (about 67 feet from edge
  line to edge line)
• TH 2 is uncontrolled
• Stop sign control for CSAH 75 and yield sign
  control for median crossover

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Data Review

• Traffic Volumes
• 7,200 to 10,600 vehicles/day on TH 2
• 4,700 vehicles/day on CSAH 75
• Intersection does not meet MMUTCD signal warrants

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Data Review

• Crash Data
• 9 crashes in four year period
• 4 crashes involved injuries
• Intersection crash rate is at the District 2
  average rate
• 5 crashes during months of January - March
• 3 crashes cited icy road conditions
• No strong pattern to type of crashes
• Winter driving conditions may be a factor in
  crashes

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Field Review

• Geometric Design and Lighting
• Sight distance limitation to east from CSAH 75
  due to signing along TH 2
• Several access points onto TH 2 east of CSAH 75
• Rumble strips on SB CSAH 75 approach to TH 2 are
  worn
• Wide driveway to convenience store on CSAH 75
  north of TH 2
• Existing street lighting only lights up north
  half of intersection
• Wide center median

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Field Review

• Signing and Pavement Markings
• Number of signs for WB TH 2 approaching CSAH 75
  creates information overload for motorists
• Not enough ONE WAY signing at intersection
• Undersized signing for expressway intersection
  conditions
• CSAH 75 route marker signing for WB TH 2 becomes
  lost in background due to guide/specific service
  signing
• Some signs mounted too low
• Approaches have centerline, edge line, and lane
  line markings
• No pavement markings in median crossover area
• No yield line markings and faded stop line
  marking
• No arrow marking for right turn lanes along TH 2

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Potential Mitigation Measures

• Short-Term Improvements
• Make intersection a priority for winter roadway
  maintenance activities
• Install additional street lighting for south side
  of intersection
• Reduce number and improve spacing of
  guide/specific service signs along TH 2 east of
  CSAH 75
• Re-cut rumble strips on SB CSAH 75
• Change CSAH 75 route marker signing to larger
  signs along TH 2 east of CSAH 75
• Add ONE WAY signs and upgrade signing to meet
  current expressway intersection signing standards
  
• Add arrow markings to right turn lanes along WB
  TH 2
• Use Follow County 75 plates on specific service
  signing

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Potential Mitigation Measures

• Long-Term Improvements
• Reduce number of access points along TH 2 east of
  CSAH 75 by providing a parallel service road
• Reduce width of convenience store driveway onto
  CSAH 75
• Add more pedestrian/bike facilities along the
  roadways in the area

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RSA Status

• Additional investigation and detailed review by
  District 2 staff required before any decisions
  concerning implementation are made
• Some mitigation measures require action by other
  agencies

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Contact Information

• Loren Hill, State-Aid Traffic Safety Engineer,
  loren.hill_at_ dot.state.mn.us, 651-282-6028.
• Dave Engstrom, State Traffic Safety Engineer,
  david.engstrom_at_dot.state.mn.us, 651-634-5100.
• Mike Kamnikar, District Traffic Engineer,
  michael.kamnikar_at_dot.state.mn.us

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Additional Information

• www.roadsafetyaudits.org
• http//safety.fhwa.dot.gov/rsa

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Thank you for attending!