Question to the Department for Transport:

To ask the Secretary of State for Transport, what assessment his Department has made of the reasons for the decline in average traffic speed over the last five years.

The Department publishes statistics on average traffic speeds on locally managed ‘A’ roads in England and the Strategic Road Network. For locally managed ‘A’ roads, average speeds have decreased since 2014, when the Department started measuring speeds over the full 24 hours of the day. This is in line with the previously published statistical series which presented average speeds, on locally managed ‘A’ roads during the weekday morning peak, decreasing from 2012 to the end of that series in 2015.

The statistics for average speeds on the Strategic Road Network start in 2015-16. The latest statistics in this series (the 12 months to June 2016) presented a small decrease in average speeds compared to 2015-16 (the 12 months to March 2016).

The Department has not undertaken a formal assessment of the reasons for the decline in average speeds. However, we believe that the decreases observed in average speeds on locally managed ‘A roads in England since 2012 are, at least in part, a result of the impact of increases in traffic on these roads. We know that people rely on roads in increasing numbers as our economy grows, and that is why, for example, we are investing £15billion in the strategic road network which will help to help tackle congestion.

In addition, in 2012-13 there were unusually high levels of rainfall in England, which we also believe contributed to the decrease in average speeds at that time.