Recent research has updated a 1998 study of the effects of traffic congestion on logistical efficiency in the UK. It has focused on the contribution of congestion to unreliability across nine sectors. The relationship between traffic flow and transit time variability has been modeled using data from the Highways Agency and speed-flow ratios. An analysis of transport KPI survey data and an interview survey of 32 managers in 24 companies have explored the relative importance of congestion, The

more »

... vey also examined the extent to which companies are adapting their logistical systems to worsening traffic congestion in the UK.