Showing papers on "Traffic count published in 1976"

Calibrating traffic models on traffic census results only

Abstract: The idea in the procedure is to calibrate the gravity model directly on the basis of the traffic census results. The only data required are traffic censuses, land-use patterns and road network descriptions. The traffic model has a simultaneous calculation of trip generation, trip distribution and assignment, giving a feedback from inter-zonal travel times to trip generation. The model is a rapid and inexpensive means of obtaining results with modified road networks and land-use patterns. The calibration method has been tested in a rural area.(a) /TRRL/

A model of inter city motor travel estimated by link volumes

Abstract: The model described in this paper was constructed for the Commonwealth Bureau of Roads. The objective was to devise a rigorous methodology for disaggregating the Australian national system of urban centres into distinct zones of economic activity; then, to use this zonation to construct a model of traffic generation for the national highways system. An important aspect of the model is that it was calibrated entirely by traffic counts. The most expensive part of any traffic modelling procedure is the assembling of the base year trip matrix from home interviews and cordon counts. Recently there have been considerable efforts to develop techniques which eliminate or minimise this input. One technique that seems particularly promising is to calibrate the traffic model by link volumes rather than a base year od matrix (a).

Short count annual average daily traffic estimation

Abstract: This paper derived from an investigation, the aim of which was to develop a system of counting on South Australian roads, and of processing this data, which would permit an increase in the number of locations at which aadt estimates could be taken, as well as increasing the accuracy of these estimates without increasing the man hours of work required. Based on a method derived by Harmelink (1968) this paper fits various models to full year count data in an attempt to follow this data with a 'smooth' curve. Several 'short term' sample counting options are then tested to determine what accuracy they will give in estimating aadt. The work was carried out by simulating traffic situations from existing full year count data and comparing estimated aadts with the known true value. /Author/TRRL/

1975 turkey traffic survey (ankara-istanbul expressway): axle loading

Abstract: An axle-load survey was carried out on the Ankara--Istanbul Expressway in Turkey in April 1975 The objects of this survey were to train a Turkish team to carry out axle-load surveys, to determine the traffic and axle loading on this route which contains a bituminous surfacing experiment undertaken by the Turkish Highway Authority in cooperation with the Transport and Road Research Laboratory and to improve knowledge of the axle-load distribution of vehicle populations in different countries Initially a five-day 24-hour continuous manual traffic count was carried out to determine the numbers and classification of vehicles using the road Traffic in each direction was then sampled and weighed, using the TRRL portable weighbridge, for 24 hours a day for five days The results of the survey showed that the average daily traffic on this road was 14,500, one-third of which consisted of trucks The mean equivalence factor was 14 standard axles per vehicle in the Ankara direction and 12 in the Istanbul direction, but there was some evidence to suggest that the true figure for the Ankara direction could be as high as 20 Approximately one-third of the vehicle s weighed had axle loads in excess of the legal limit of 82 tonnes and it is estimated that these do about 85 percent of the damage to the road pavement The mean damage per tonne of payload carried compares favourably with that found in other countries in which the Laboratory has carried out surveys