The Department does not operate traffic signals in “flash mode” for the following reasons:
- Standard traffic engineering practice is to only flash signals for emergency conditions, or prior to a new installation. An emergency condition can occur when the electronic monitor detects a problem with the traffic signal controller and automatically places the traffic signal in flash mode.
- In general, the traveling public recognizes the signal flash mode as a malfunction and not as normal operation.
- The traveling public is unclear on how to travel through a signal in flash mode; some treat the condition as an all-way stop and others as a side street stop; and as a result a safety risk is created and unnecessary traffic delays can occur.
Alternatively, the Department accommodates side street traffic during light traffic conditions by operating signal systems in either a very short cycle length of approximately one minute, or by operating signals in “free mode” which permits a rapid change from the main street green to serve arriving side street traffic.