Excerpt from an e-mail sent FDOT engineer Mark Wilson to 10 News Investigator Noah Pransky on Monday, May 13:
Any local agency can request to the FDOT District Office to use a yellow clearance time that is more than the minimum values in TEM 3.6, and if they have the documented "engineering justification" for the increased yellow clearance time, then the District Office can review this request and approve this request.
Generally speaking, if a local agency provides information from a Fl PE that was based on their observations or studies, or their review and understanding of any nationally accepted research studies, that can be shown that the data is also related to Florida drivers in their jurisdiction, then FDOT would approve this request.
Based on FDOT's review of current and past national research, where some was conducted in Florida, and FDOT's understanding of the relationship of the factors in the ITE Formula and the current TEM 3.6 minimum values; I would say that FDOT would have no problem with approving an increase of up to 0.5 seconds. Which is based on our understanding of the Perception-Reaction-Time for all drivers in Florida and deceleration rates for heavily loaded trucks.
Increases in excess of 0.5 seconds would need more documentation, like a specific traffic study at individual intersections that showed that the minimum TEM 3.6 values plus 0.5 seconds did not provide adequate time for all drivers to stop during the yellow clearance time before entering the intersection, then we would agree to increase the yellow clearance to the requested amount
Original stories on short yellow lights:
Florida quietly shortened yellow light standards & lengths, resulting in more red light camera tickets for you
Short Yellow Lights: Tampa council taking action
Federal yellow-light standards ignored on many Florida roads
Hillsborough County to study short yellow lights, federal guidelines after 10 News investigation; City of Tampa won't
10 News Investigators: Legislators acting quickly on short yellow light investigation