Systematic scientific research on highway capacity started in Finland during the 1960s. From the beginning, vehicle speeds have been actively studied. In the 1970s a wide before-and-after analysis of general road section speed limits was done followed by an analysis of lowered wintertime speed limits during the late 1980s and early 1990s. Highway capacity, on two-lane roads and on motorways, has been actively researched especially in the 1980s and 1990s. At the moment three-lane highways (with the centre lane given alternately for one direction of flow only) and exceptionally wide lanes (5.25 m) on two-lane highways are being demonstrated and studied. A special project of wintertime effects on traffic is going on and a traffic monitoring system of 180 automatic speed and flow measuring points is in use for census and research purposes. New research on signalised and non-signalised intersections is starting, partly to update old capacity values, and partly to calibrate and validate the Finnish HUTSIM microscopic simulation program. Interest in simulation is growing, and among others, the Australian TRAffic on Rural Roads TRARR program has been used in traffic flow research. (A)
Samenvatting