ARCADY

ARCADY is the acronym for (Assessment of Roundabout Capacity And DelaY). This software, produced by the Transport Research Laboratory (UK), models traffic capacity, queues and delays at roundabouts. The software is largely based on empirical relationships which were the result of extensive research carried out on existing roundabouts on the UK road network, as well as controlled test track facilities over a period of over a decade.

The program is used by traffic engineers when assessing existing layouts or when analysing the impacts of proposed design changes. Estimates of annual accident frequencies can also be obtained.

ARCADY is listed in the UK's design manual for roads and bridges.

RODEL is similar to ARCADY and utilises TRL equations under licence from TRL.

Papers on ARCADY:

• Kimber, R.M., The Traffic Capacity of Roundabouts, TRL Laboratory Report LR942, 1980.
• Maycock, G. and R.D. Hall, Accidents at 4-Arm Roundabouts, TRL Laboratory Report LR1120, 1984.
• TD 16/93, Geometric Design of Roundabouts, U.K. Department for Transport, 1993.