Greg Mauz 80bc9bbb on FHWA-2010-0159-0001

As a traffic safety researcher for 24 years there is DEFINATELY a problem with traffic signal timing in America.

Yellow timing is dangerously short.

Institute of Transportation Engineers MINIMUM Yellow Interval Lengths

Kinematic Model
Approach speed (85%ile)        Seconds          

25 MPH                                  3.0
30 MPH                                  3.3
35 MPH                                  3.6
40 MPH                                  3.9
45 MPH                                  4.3
50 MPH                                  4.7
55 MPH                                  5.0
60 MPH                                  5.4

These times do NOT include wet weather, downhill approaches, large trucks and slower than average drivers. Underposted speed limits, unethically low 1 second perception/reaction times, red clearance replacing yellow and unsynchronized signals all cause more violations and serious crashes. MINIMUM yellows should be a starting point, NOT an ending point. Lowest yellow should be 4.0 seconds at 25 MPH. Left turn yellows should also be 4.0 seconds, plus. Photo enforcing these extremely flawed yellow times is malicious entrapment.

One added second of yellow to any light reduces violations 40-80% and unlike RLTCs actually reduces crashes by 25-50% (AAA Detroit, Texas Transportation Institute, San Francisco, etc). Cameras often require over a year of enforcement to reduce RLVs by 30% (Garland, TX "Model Program"). However, yellows "astonishing results" (Detroit quote) start happening in 12 minutes, NOT 12 months! see: Truth and conclusion chapters in "Camera Enforcement -A Picture of Fraud."   http://www.bhspi.org/mauz/PictureOfFraud.pdf

As you can plainly see, longer yellows greatly increase safety! The FHwA needs to do a better job of making sure cities use longer yellows!

Check out more of my research at http://www.bhspi.org/mauz/

Page 1
 

Subscribe to this comment's feed

Title
Comment	smaller | bigger
Name
Email
Write the displayed characters
Subscribe via email (registered users only)
	Add Comment Preview