Traffic signals do not always reduce or prevent accidents and are not always as asset to traffic control. 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:
1. Are there so many vehicles on both streets that controls are needed to assign R.O.W. or relieve congestion?
2. Is the traffic on the main street so consistently heave that drivers on the side street must try to cross when it is unsafe?
3. Are there some many pedestrians trying to cross a busy main street that confusing, congested, or hazardous conditions result?
4. Are there so many school aged children trying to cross the street at the same tiems that they need special controls for their supervision or protection? If so, is a signal the best solution?
5. Are signals at this location going to help drivers maintain a uniform pace along the major street without being stopped unnecessarily?
6. Does the collision history indicate that a signal will reduce the probability of driver actions which cause collision?
7. Is the character of the minor street such that additional traffic attracted by the existence of a signal, desirable to the adjacent neighborhood?
8. Is there a combination of the above conditions and factors which indicates that a traffic signal will result in improvement rather than a detriment?
*For more details on this subject please go to the Traffic Engineering Web page and look under Additional Information and then click on this topic.