Cameras are not needed at every intersection or along every corridor because studies have found them to have a “halo” or spillover effect on surrounding locations, and a general deterrence effect jurisdictionwide, if the program is intensive enough. There is no optimal number of cameras that has been identified, although there is recent research confirming that more intensive programs have larger benefits. Agencies should consider how many camera systems would be required within their jurisdiction so that the members of the community see and understand that the enforcement is real. The ideal program includes a high degree of public awareness with enough actual enforcement to encourage voluntary compliance with the law throughout the jurisdiction, not just at enforcement locations.