1. 9-1 LOW COST SAFETY IMPROVEMENTS Practitioner Workshop Exercise C – Session #9

2. 9-2 Traffic Signals – Exercise XII: Naper Blvd and Plank Rd Learning Outcomes: 1.Analyze traffic crash crash and other engineering information 2.Select appropriate low cost safety and engineering Countermeasures

3. 9-3 Traffic Signals – Exercise XII: Naper Blvd and Plank Rd Remedy of Naper Blvd & Plank Road Traffic Signal Northbound Naper Blvd at Plank Road

4. 9-4 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

5. 9-5 Traffic Signals – Exercise XII: Naper Blvd and Plank Rd Remedy of Naper Blvd & Plank Road Traffic Signal At 450 feet back MUTCD Requires 460 feet of visibility Southbound Naper Blvd approaching Plank Road

6. 9-6 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

7. 9-7 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

8. 9-8 Traffic Signals – Exercise XII: Naper Blvd and Plank Rd  Speed limit on Naper Blvd is 40 mph; 85 th 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

9. 9-9 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.

10. 9-10 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

11. 9-11 Questions? Exercise