1. SPEED PHOTO-RADAR ENFORCEMENT High Value Research in Illinois

2. Just the Facts, Ma’am WHAT? SPEED PHOTO-RADAR ENFORCEMENT WHO? Dr. Rahim Benekohal WHERE? University of Illinois at Urbana-Champaign WHEN? 7/1/2005 - 6/30/2008 HOW MUCH? $309,000

3. What We Looked At Speed photo-radar enforcement (SPE) vs. traditional methods Police presence (with/without patrol lights on) Speed display trailers Combination of police presence/speed display Determine effects on Traffic flow characteristics Safety in work zones

4. What is SPE?

5. What We Looked At Two interstate work zones Effect at treatment location Spatial effects Impact on speed 1.5 miles down the road Temporal (halo) effects Impact on speed 40-60 minutes after treatment removed

6. What We Found SPE significantly reduced speed of cars and trucks in work zone SPE did have spatial effects SPE reduced speed/percentage of speeders downstream from treatment SPE had limited halo effect; police presence had none SPE was most effective treatment

7. Implementation Illinois has implemented SPE statewide Specially trained state police officers Deploy SPE vans Review/approve violations for citation issuance Appear in court for adjudication of all approved work zone citations Illinois has expanded SPE One van for each IDOT region (5 total)

8. Questions? Amy Schutzbach Engineer of Physical Research Illinois Department of Transportation Amy.Schutzbach@illinois.gov (217) 782-2631