The clever traffic models to blind us with science

Mathematical models can be great tools when applied correctly. But a model is only useful if it’s predicted outcomes are similar to those observed in real life.

The applicant’s Transport Assessment claims the plan would not have a big impact on the traffic through the Heath, partly justified by mathematically modelling junction behaviour.

The problem is that the junction modelling considers each junction individually. It does not consider the local road network as a whole. Local residents are all too familiar with the queues that form at peak times from the Fleet Road/ Elvetham Heath Road and Fleet Road/ Elvetham Road roundabouts, through the Elvetham Heath Way/ Mounts Way roundabout, all the way through and beyond the Morrisons roundabout. This is how it is in real life.

The links between the junctions are relatively short and so traffic regularly blocks back to upstream junctions. This means the flow and waiting times predicted by modelling these junctions individually do not reflect the current real life experience of crawling from the Morrisons roundabout to Fleet Road and beyond during the morning peak.