The reality of driverless vehicles using UK highways may not be that far off. Understanding what this means for our highway community and how and when to adapt our approach to infrastructure asset management is vital. More specifically for HTMA members and the highway maintenance community, how to predict future travel behaviour arising from CAV, technology requirements and the impact on existing highway infrastructure is critical. Better understanding will allow timely adaptation strategies and investment cases to be developed to minimise cost, disruption and to maximise opportunities.
 
HTMA has been researching the potential impacts of driverless vehicles and CAV technology on UK highways and the highway maintenance sector. As part of our research we asked UK organisations associated with the highways industry whether they have considered the impacts to their businesses and the wider community, what they think are the key challenges to highway owners, operators and suppliers and what direction and information they still need or anticipate needing to be able to develop adaptation strategies.
 
The key findings of our research show that when CAV is fully implemented there will be significant changes to the needs and demands of highway infrastructure and therefore the requirements of industry to support it. The transition period to an interim driverless environment will also bring significant uncertainties, challenges and risks. But this transition will allow opportunities, most of which are yet unknown, supporting the highways sector to become more efficient through adaptation.
 
HTMA’s survey of 22 organisations working in the UK highways industry showed that two thirds have considered the impact of CAV vehicles on the highway network. The shift to digital technology infrastructure is a key area of adaptation along with maintaining road safety. Other discussion areas are the integration of technology with different highway boundaries, from verges to solid concrete VRS, and the future role of road markings and safety signage.
 
When asked about the main challenges of introducing CAV, organisations highlighted the interaction between highway condition and weather conditions and having a consistently safe driving environment.  Other challenges included how to navigate in unmarked, variable width country lanes. And how will autonomous vehicles deal with poor road markings, signs, road condition, and how will the vehicles react in a 'crash' situation. And in a transition state, how autonomous vehicles and human controlled vehicles will collaborate and communicate.
 
The information that organisations still require or anticipate needing to be able to plan for the roll-out of connected automated vehicles was again consistent. Requirements focussed on who in industry will lead this transition, how vehicles will interact with the highway environment, directives from Government on timelines, directives from industry on infrastructure needs, more information from vehicle manufacturers, guidelines on network communication and structure implementation on interim and future highways.
 
To supplement its research HTMA has been cataloguing other views. For example, the recent US AASHTO debate into the interaction between CAV and infrastructure, the potential benefits to infrastructure owners and the preparedness of US states to introduce a driverless environment. Potential benefits include narrower lanes and hard shoulders through more precise driving and increased throughput, including increased capacity at traffic-controlled junctions. Also reducing on-street parking to free up space for pedestrians and cyclists were seen as potential further benefits.
 
Other research of relevance to highway maintenance is the platooning of heavy goods vehicles, which is seen as a key CAV benefit.  The technology for vehicles to connect digitally and travel as a platoon with closer tail to nose distances is already a reality but the consequences of structural damage to pavements caused by more frequent stresses and the inability for current pavement designs to recover is unknown. This may even test the fatigue limits of our ‘long-life’ pavement designs.
 
HTMA will continue its research and is seeking to further collaborate with other organisations interested in understanding what CAV means for UK highways, including the impact on maintenance, and the preparation of adaptation strategies. Although the journey towards a fully driverless environment seems inevitable, the timescales and transition are less certain but will probably happen sooner than we think.