LOW COST SAFETY IMPROVEMENTS

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LOW COST SAFETY IMPROVEMENTS
Practitioner Workshop Exercise C Session 9
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Exercise

• Learning Objectives
• Analyze traffic crash crash and other engineering
  information
• Select appropriate low cost safety and
  engineering Countermeasures

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Traffic Signals Exercise XII Naper Blvd and
Plank Rd

• Remedy of Naper Blvd Plank Road Traffic Signal

Northbound Naper Blvd at Plank Road
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Traffic Signals Exercise XII Naper Blvd and
Plank Rd

• Remedy of Naper Blvd Plank Road Traffic Signal

Southbound Naper Blvd approaching Plank Road
At 280 feet back from Stop Bar
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Traffic Signals Exercise XII Naper Blvd and
Plank Rd

• Remedy of Naper Blvd Plank Road Traffic Signal

MUTCD Requires 460 feet of visibility
At 450 feet back
Southbound Naper Blvd approaching Plank Road
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Traffic Signals Exercise XII Naper Blvd and
Plank Rd

• Remedy of Naper Blvd Plank Road Traffic Signal

Southbound Naper Blvd at Ogden Av toward Plank
Road
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Traffic Signals Exercise XII Naper Blvd and
Plank Rd

• Remedy of Naper Blvd Plank Road Traffic Signal
• The intersection of Naper Blvd with Plank Road
  was improved to traffic signal control in 1985
  with the construction of Naper Blvd, a new 4 lane
  major arterial connecting south portions of
  Naperville, IL to the Illinois Tollway
  interchange to the north.
• Plank Road is collector street with 5,500 ADT
• Traffic crash experience averaged 15 per year
  with 6 to 8 serious injury crashes for the years
  1985 thru 1991
• Traffic volumes on Naper Blvd started at 12,000
  ADT in 1985 and grew to 28,000 ADT by 1991

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Traffic Signals Exercise XII Naper Blvd and
Plank Rd

• Speed limit on Naper Blvd is 40 mph 85th
  percentile speeds are 48 mph speed limit on
  Plank Road is 35 mph.
• Traffic signals were added to the north of this
  signal and a closed loop signal system was
  installed in late 1991.
• Traffic volumes on Naper Blvd started at 12,000
  ADT in 1985 and grew to 28,000 ADT by 1991.
• Traffic crash experience averaged 15 per year
  with 6 to 8 serious injury crashes for the years
  1985 thru 1991
• In early 1992, a multi-vehicle crash with
  fatalities was followed by two fatal crashes
  1993 had 4 fatalities, 9 serious injury crashes
  out of a total of 28

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Traffic Signals Exercise XII Naper Blvd and
Plank Rd

• Visibility of the signals was a significant
  issue southbound traffic could not see the far
  side indications until a point 280 feet from the
  stop bar visibility of the northbound signals
  was slightly better at 350 feet.
• Review of the engineering plans identified that
  the signal design was for tangent approaches the
  actual conditions in the field were a reverse 35
  mph 6 degree curve.
• Signal heads were far side only with 12
  sections and backplates
• Review of Clearance Intervals (Yellow and Red)
  was carried out for 45 mph approach speeds and
  found to be consistent with ITE practice.

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Traffic Signals Exercise XII Naper Blvd and
Plank Road

• What low cost safety countermeasures would you
  consider?
• What is the safety effect (CRF) for each?

Discussion
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Traffic Signals Exercise XII Naper Blvd and
Plank Rd

• Case Study J Remedy of Naper Blvd Plank Road
  Traffic Signal

Signal Timing /Coordination and Visibility
Improvement
Additional Supplemental Near-Side Signal
Northbound Naper Blvd at Plank Road
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Traffic Signals Exercise XII Naper Blvd and
Plank Rd

• Case Study J Remedy of Naper Blvd Plank Road
  Traffic Signal

Signal Timing /Coordination Visibility Improvement
Advance Warning Sign with Yellow Flasher
Southbound Naper Blvd approaching Plank Road
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Traffic Signals Exercise XII Naper Blvd and
Plank Rd

• Case Study J Remedy of Naper Blvd Plank Road
  Traffic Signal

Signal Timing /Coordination and Visibility
Improvement
Additional Supplemental Near-Side Signal
Southbound Naper Blvd at Plank Road
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Traffic Signals Exercise XII Naper Blvd and
Plank Rd

• Case Study J Remedy of Naper Blvd Plank Road
  Traffic Signal

Signal Timing /Coordination Visibility Improvement
Additional Supplemental Near-Side Signal
At 450 feet back from Stop Bar
Southbound Naper Blvd approaching Plank Road
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Traffic Signals Exercise XII Naper Blvd and
Plank Rd

• Case Study J Remedy of Naper Blvd Plank Road
  Traffic Signal

Signal Timing /Coordination Visibility Improvement
Additional Supplemental Near-Side Signal
Southbound Naper Blvd at Ogden Av toward Plank
Road
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Traffic Signals Exercise XII Naper Blvd and
Plank Rd

• Case Study J Remedy of Naper Blvd Plank Road
  Traffic Signal

After Crash experience is 8 crashes per year or
less for 1996-2002 with no serious injury or
fatals
Signal Timing /Coordination Visibility Improvement
Advance Warning Sign Be Prepared to Stop with
When Flashing Plaque with Flasher tied to
Controller
Northbound Naper Blvd approaching Plank Road
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Exercise

• Learning Objectives
• Analyzed traffic crash crash and other
  engineering information
• Selected appropriate low cost safety and
  engineering Countermeasures

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Exercise

• Questions?