Beca have been commissioned by the REG to assist with a best practice guideline for updating traffic estimates. This guideline follows on from a separate report investigating how different industry participants update estimates currently. This initial report was titled “Traffic Monitoring Estimation Update Guidelines – Best Practice Review”. This report found practices varied although all followed a similar framework with different methodologies at different stages of the process. This depended on both of their various preferences as much as the type of network they were typically dealing with.

The purpose of this report is to outline a process to follow while also detailing many of the current methods used in the industry for updating traffic estimates in RAMM. This reflects both the varied practices which all have their merits, but also to reflect the variability in the complexity and nature of each road network.

These guidelines are to help the asset manager, seeking a process to follow to assign estimates to their network and discuss some of the concepts involved. It is not a comprehensive guideline to assist the experienced practitioner nor cover more advanced and complex techniques that would be justified on a large, complex road network.

It is important to note that these guidelines are very much targeted at local authority networks. State Highway networks require a completely different approach. State Highway networks have fewer roads as such and often four counts per site per year from which to generate estimates. Local authority networks tend to have lots of different roads and fewer counts per km so much more emphasis is on sampling to gather count information to estimate flows on the network. The State Highway network also follows a set prescribed process which does not need a guideline to cover it.