Traffic signals are recognized as not a cure for every traffic problem. The installation of a traffic signal will not eliminate congestion or collisions, nor are they an effect means to reduce vehicle speeds. Traffic signals are not always an asset to traffic control. In some instances total accidents and the severity of accidents, increased after traffic signals are installed.
When can a traffic signal be an asset instead of a liability to safety? In order to answer this, traffic engineers have to ask and answer a series of questions:
To help traffic engineers answers these questions, they compare the existing conditions (road classification, volume, pedestrian activity, tec.) against nationally accepted minimum guidelines. These guidelines called "Warrants" are established in the Federal publication of the Manual on Uniform Traffic Control Devices (MUTCD). Through ordinance the City and County of Denver has adopted the use of the MUTCD.
A traffic signal that decreases accidents and improves the flow of traffic is an asset to any community. On the other hand, an un-warranted traffic signal can be a source of danger and annoyance to all who use the intersection; pedestrians, bicyclists and drivers alike.
Street Lights or Street Lamps come in a variety of shapes, styles and sizes, but in general, the term refers to the lights that are on the sidewalks or the sides of streets and shed light on the right-of-way.