Design hourly volume estimation at freeway nodes using floating car data

Abstract

The estimation of the Design Hourly Volume (DHV) is an essential step for a traffic assessment. At freeway nodes, not all ramps are detected by permanent traffic count (PTC) stations. Therefore the German HCM recommends additional short-term counts (STC) to determine the DHV. Since conducting STC is usually associated with high effort, the question arises whether the information obtained by STC can also be derived from Floating Car Data (FCD). We propose an approach for processing the FCD in order to apply it instead of the STC for the determination of the DHV at ramp junctions. The performance of the method is evaluated on five nodes, for which FCD from 2017 and a reference database covering all 8,760 hourly volumes of all ramps and main lanes of the road section are available. The result show, the usage of representative FCD days is possible.