UK study finds that building narrower freeway lanes to accommodate enhanced route-tracking capabilities of connected and autonomous vehicles could result in cost savings of $600K (USD) for every km of road length built.
Study investigates the potential benefits of CAVs in infrastructure costs
Date Posted

CAVs could mean cheaper roads

Summary Information

A study by the UK's University of Southampton’s Transportation Research Group (TRG) assessed whether connected and automated vehicles (CAVs) could be accommodated by building narrower freeway lanes. Earlier studies in the field of CAV highway provisions have been based on existing design standards, or on roads built without taking into account vehicles’ close route- tracking capabilities. To fill this gap, the research team applied data from wheel odometry-based 3D Lidar, inertial measurements and a GPS-based locating unit to a truck with onerous vehicle space demands to identify the additional space allowance that would be needed to cope with the minor tracking deviations that such a vehicle would inevitably make.

The team identified a 22-km section of the planned Lower Thames Crossing located just east of London to use as a case study to demonstrate the beneficial cost impacts of an alternative, "less onerous" geometric roadway design.

The study applied standard construction industry bills of quantities techniques to calculate the materials, plant, labor and time-cost elements of contracts for building out both the standard and the CAV-friendly versions. It used detailed engineering design drawings that national road operator Highways England (HE) had produced for use in a 2018 public consultation. The results appear in the table below.


Table 1: Construction cost savings on CAV-friendly roads



Item Cost Saving (US $m)
Pavements 7.4
Earthworks 1.6
Bridges/viaducts 3.5
Land take 0.1
Total Savings for 22 km segment 12.6
Savings per km of freeway-standard construction 0.6



Goal Areas
Deployment Locations