Optimised Signal Capacity and Delay, Phase-based Rapid Optimisation of traffic signals

OSCADY PRO

OSCADY PRO v1.2 now available - click here for release notes

Click here for screenshots

OSCADY PRO, launched in late 2006, is a phase-based traffic signal optimisation program.   OSCADY PRO has been developed in conjunction with the Centre for Transport Studies at UCL (University College London). The software makes use of a number of unique optimisation techniques and can be used for isolated junctions, or the results can be exported into TRANSYT for use in linked systems.

OSCADY PRO allows the import of files from OSCADY Classic (previously known as OSCADY 5).

A significant advantage of OSCADY PRO is that it can automatically generate and optimise stages and stage sequences.  All that is needed is for the user to supply minimum intergreen times in the form of an intergreen matrix; the program does the rest and calculates all possible optimum stages and stage sequences.  From this starting point, the program then produces sets of individual phase timings that maximise capacity and/or minimise delay.  Phase delays and repeated greens are automatically handled by the program.

In its simplest form, therefore, the user can produce phase and stage timings very easily simply by providing an intergreen matrix and traffic flows.  This removes the need for the user to manually input stages and sequences.  At large or complex junctions, the best stage sequences can be very difficult to find manually, and so OSCADY PRO’s automatic system is invaluable.  Furthermore, it can often identify solutions that may otherwise have been overlooked but give superior performance in terms of capacity/delay.  

Of course, OSCADY PRO allows the user to input stages manually when an existing junction is being evaluated or when it is necessary to force a particular stage.

Key modelling features

• Stage and sequence generators
• Up to 20 arms, with 20 traffic streams on each arm, plus 20 pedestrian streams and 20 phases can be modelled
• Optimises for three objectives: Critical cycle time, maximum capacity and minimum delay
• Filter lanes / indicative arrows, short (flared) lanes and opposed right turners can all be modelled
• Geometric delay calculated for each traffic stream
• Accident prediction for 3 and 4-arm urban junctions
• Phase constraints can be added to force pairs of phases to start/end together
• Works with fixed or maximum cycle time; each stage and phase can have min/max greens applied as well as various other restrictions such as maximum acceptable queue and degree of saturation
• Multiple demand sets can be defined, with each profile specified as either ODTAB, LEVELS, FOUR, DIRECT or FLAT. Each set can be defined in terms of a relationship to another set, which is automatically re-calculated
• Automatic lane grouping – the program can analyse traffic streams and flows and suggest the optimum arrangement of lanes and streams
• Time varying flows can be modelled
• Evaluation mode (allowing existing timings to be analysed)
• Drive-on-the-left / drive-on-the-right
• Saturation flow estimation for each traffic stream
• Phase timings can be shown to an accuracy of 0.1s
• Provides an output compatible with the TR2500 form used to specify controller configuration.

Graphical User Interface Features

• Highly visual and dynamic GUI.  Any number of windows can be shown at once, all of which are automatically updated (and the file re-run) whenever data changes
• Junction Diagram – shows the junction in graphical format and includes queue animation, signal states, phases, stages, and results such as delay for each stream.  The junction diagram allows access to all data for traffic streams and phases etc, and enables a new junction to be built graphically
• Phase timings diagram – shows phase and stage timings graphically, along with phase delays and intergreens
• Graph Generator – Allows any result (effective green time, delay, etc) to be plotted against any input parameter (cycle time, sat flow, etc).  This serves as a very flexible sensitivity analysis tool
• Report Generator – reports are generated in HTML, in a format that can easily be pasted into a word processor or spreadsheet.  The main diagrams are inserted in vector format, meaning that print-outs are very high quality
• Undo/redo allowing stepping back through up to 100 changes
• Quick edit mode – allows main data to be edited in a spreadsheet format
• All data can be accessed via a ‘tree view’ system and is therefore accessible from anywhere in the program
• Export to TRANSYT 12
• Importing from other well-known products including OSCADY Classic  

TRL wish to acknowledge the valuable support of our partners at the Centre for Transport Studies at UCL in the development of this new and exciting product.