Recent research concerning rural road traffic in west Germany

The first part of this paper describes research activities concerning intermediate cross section roads whose capacity and level of service lies above typical rural roads but below those of the most narrow type of motorway. The range of application of these kind of cross sections is designed for about 12,000 to 18,000 veh/ 24h (aadt). According to preliminary results, the safest traffic flow is achieved on a special intermediate type of rural road having an oversized lane width. First experiences made on two and a half lane rural roads allow us to expect a similarly high level of traffic safety. In summary, the intermediate cross sections allow easier overtaking in comparison to typical rural roads. The second part deals with special measurements of overtaking slow moving vehicles (farm tractors travelling less that 25 km/h) on rural roads. The measurements were performed by means of three video cameras and a radar meter mounted on a slow moving test vehicle. The results permit a complete description of overtaking manoeuvres. The results further give answers to some more questions and the opportunity for validating a simulation model (a).