The growing potential for providing road user with realtime traffic and route information creates the problem of where to put additional variable signing. Because `prime' locations along motorways will already be occupied by existing signing, it may often just not be possible to position variable message signs at their intended locations. A straightforward solution to the problem is to simply add the variable message signs to whatever else may already be in place at a location. The present study investigates the consequences of putting various forms of variable and fixed information on top of each other for the capacity of users to pick up information from the respective sources. Anticipating possible negative effects the study also evaluates certain possibilities of counteracting the overload resulting from massive stacks of information. (A)
Abstract