Did you know?
The world’s first traffic signal was installed on Dec. 9, 1868, near the Houses of Parliament and the Westminster Bridge. Then in 1920, William Potts, a Detroit police officer, added the amber “caution” light.
Signalization is one the the most cost effective strategies known to improve the overall efficiency of traffic flow, be it actuated or non-actuated. Used effectively, signalization can yield many benefits. The most obvious being a reduction in delay and driver frustration. Reducing the amount of stops decreases fuel consumption which results in less emissions and cleaner air. In addition, keeping traffic flow efficient along main arterials reduces the number of motorists diverting into residential areas and thereby reducing the number of potential incidents within.
Traffic patterns are ever changing and are only effective as long as the parameters used to create the study remain constant. As a rule, timings, phasing, and controller up dates should be reviewed yearly. A great time to do this is during one of Can-Traffics yearly or bi-annual maintenance programs(provide link) This is especially important in developing areas or areas with sustained growth.
Another advantageous benefit of signalization is the complimentary utilization of vehicle preemption. Preemptive signals allow the safe passage of emergency vehicles, buses, trains and other commercial vehicles through their respective corridors.
Improper use of signalization however can have a negative impact on overall traffic efficacy. This can occur due to insufficient programming or phasing. The result can be an increase in travel time, non-compliance with signal indicators, increased traffic in surrounding areas in a effort to avoid the control device or possibly an increase in rear end collisions. Drivers can also become increasingly frustrated, driving impatiently and making poor judgment decisions. Fortunately, there are many techniques to mitigate these circumstances. The fourteenth edition of The Fundamentals of Traffic Engineering outlines many of these techniques;
-Prohibiting a turning movement
-Providing turn lanes
-Installing or providing warning signs
-Improved roadway lighting
-Providing a stop sign
-Installing or improving pedestrian crosswalks
-Improving skid resistance for wet-weather accidents
-Creating truck escape ramps
-Providing rumble strips and,
-Correcting the roadway curve
As each intersection is unique, it is important to consider the parameters that warrant the installation of signals ( see Manual On Uniform Traffic Control Devices). This alongside a comprehensive engineering study will help insure you achieve the best result.