The Sustainably Safe approach requires that, in principle, a parallel (residential access) road must come next to provincial distributor roads. If there already is a parallel road, then an overtaking prohibition can be introduced to the distributor road. Socially, spatially, and financially, the building of parallel roads, in combination with overtaking prohibitions, is only attractive if this also has demonstrable, relevant road safety effects. Moreover, the quality of the traffic distribution must be better. Special attention is required for the effect of agricultural traffic. Based on a number of studies and micro simulations, this article analyses various bottlenecks of, and solutions for, road safety on provincial roads. 80 km/h roads with a complete vehicle type exclusion ruling, referred to henceforth as "VOL roads", and roads with a partial vehicle type exclusion ruling, the so-called "GED roads", are dealt with. VOL roads are closed to horse riders, livestock, carts, motor vehicles with a maximum speed of 25 km/h, 1-seat cars with a moped engine, (light) mopeds, and vehicles for the handicapped. GED roads are closed to (light) mopeds and vehicles for the handicapped. The analyses make it possible to conclude that: (1) The speed of cars and lorries on GED distributor road segments is strongly dependent on the number and speed of agricultural vehicles; (2) Agricultural vehicles cause a slower segment speed, which endangers the network function; (3) Agricultural vehicles result in a large distribution of speeds, so that road safety is put under strong pressure; and (4) that the number of vehicles in close groups and the number of overtaking manoeuvres is strongly influenced by the traffic conditions. This point especially, needs extra attention.
Samenvatting