Regarding speed management and control, a number of effective interventions have been identified that provide concrete benefits in reducing accidents and reducing accident consequences when properly implemented.
Legislative and deterrent supervision: Two of the most effective measures to reduce injuries and deaths on the road are to determine speed limits and to control them effectively and widely. Experiences in many different countries show that defining the legal speed limits is only a prerequisite.
Unless speed is controlled by continuous and visible methods, determining the legal speed limits has only a short-term effect in reducing speed.
However, if continuous and common, the control is based entirely on visible methods, there is an undesirable result in terms of deterrence: the driver takes into account the “visible” hints that it is or may be the control, and adjusts its behavior accordingly.
More precisely, establishing police supervision entirely on visible methods and strategies means marking the routes where it is and is not being supervised, and violations are increasing where there is no control.