Junction & Signal Design

TRL’s traffic design software packages are some of the most commonly used in the world, underpinning a variety of assessment and modelling work in over 110 countries including; India, America and Australia.

ARCADY, PICADY & OSCADY are components of the modular Junctions package for designing and modelling priority junctions, such as roundabouts and crossroads. All three modules are available and licensed jointly:

ARCADY is used for the assessment of roundabouts. It accurately predicts accident rates, capacity, queue and delay (both queuing and geometric) for almost any size of roundabout, ranging from multi-armed grade separated roundabouts, to mini-roundabouts in suburban locations.

PICADY  incorporates TRL’s extensive research into junction design issues and predicts accident rates, capacities, queue lengths and delays (both queuing and geometric) at non-signalised major/minor priority junctions.

OSCADY provides evaluation and optimisation of simple isolated signalised junctions. If combined with an ARCADY roundabout in Lane Simulation mode, it can also be used to evaluate partially signalised roundabouts.

TRANSYT determines optimum, coordinated traffic signal timings and is suitable for urban intersections and networks, signalised or unsignalled roundabouts and motorway intersections. Its use around the world reflects its international applicability and the latest version builds on existing ability; TRANSYT is no longer just a network modelling tool – specific tools such as the lane-designation facility greatly assists in the design of signalised roundabouts.  Basic adaptive control (roadworks, system ‘D’) can also be modelled through TRANSYT’s ability to model the triggering of demand dependant stages in simulation mode.

Geometric measurement tool in ARCADY