Speed reducing construction jolts the vehicle driving at a too high a speed in an unpleasant way. This report deals with two speed reducing constructions, a hump and an elevated pedestrian crossing. Attempts have been made to seek for these constructions and for each vehicle type, a typical limit speed which causes discomfort or makes the control of the vehicle dirficult during braking. The elevated pedestrian crossing does not hamper the control of any tested vehicle and the hump only the control of an empty delivery van when braking at speeds exceeding 40 kmph. The hump is intolerably uncomfortable for heavy vehicles already at speeds below 40 kmph and an elevated pedestrian crossing at speeds exceeding 40 kmph. The hump was at none of the speeds investigated intolerably uncomfortable for passenger cars. Without hampering the controlability of the vehicle the elevated pedestrian crossing can be used as a speed reducing construction, but the hump affects the control of some vehicle groups in certain extreme situations.
Samenvatting