Roadworks on single carriageway roads often restrict the movement of the traffic to alternate one-way operation along a single running lane. This report introduces a method of selecting a suitable means of operation of the shuttle lane for a range of site and traffic conditions. The means considered are uncontrolled entry to the shuttle lane and controlled entry by use of priority signs, by fixed-time and vehicle-actuated portable traffic signals, and by signals incorporating a suggested improvement to the existing signal cycle ('conditional go'). selection is based on a comparison of steady state delay/flow curves which have been generated using a calibrated computer simulation model. The parameters used in the model have been obtained from studies of the operation of the systems at sites on the public road and on the test track at Crowthorne. (Author/publisher)
Abstract