Should we use SCATS MF to calibrate SIDRA Saturation Flow? 

Aerial photograph of road

Should we use SCATS MF to calibrate SIDRA Saturation Flow? 

We have published a new technical report on the use of the SCATS Maximum Flow (MF) parameter to calibrate SIDRA Saturation Flow.

There has been an emerging trend for SIDRA users to calibrate Saturation Flow in modelling existing signalised intersections to match the value of Maximum Flow measured and recorded in the SCATS traffic control system (SCATS MF). While the concept of SCATS MF is similar to Saturation Flow, there are significant differences in how they are measured and applied.

The report discusses in detail that valid values of SCATS MF are not available for many lanes, and where they are available, there are serious problems in translating SCATS MF to a reliable Saturation Flow value. Consequently, it recommends that SCATS MF should not be used to calibrate SIDRA models. Instead, standard values of Basic Saturation Flow should be used, and models should be calibrated and validated against observed traffic performance measures.

We thank our colleague David Nash for the research he conducted for the findings included in this report.

We also published this video on this topic on a presentation by David Nash at the AITPM Online Technical Conference Series November 2022.


NASH, D., AKÇELIK, R., BESLEY, M. and ESPADA, I. (2023). Use of SCATS MF to Calibrate SIDRA Saturation Flow. Technical Note. Akcelik and Associates Pty Ltd, Melbourne, Australia.

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