Reducing the ice hazard on smart motorways

This co-designed project with Highways England will reduce the ice hazard on motorways. As part of a nationwide trial of smart motorways, 'all lane' and 'hard shoulder running' are being used to increase capacity on critical sections of the GB motorway network. However, this approach, along with traditional road widening, has implications for winter road maintenance strategy. Significant surface temperature differences exist between lanes on motorways and it is not uncommon to find a difference of 2C between the inside and outside lane of the motorway. For example, in the case of hard shoulder running, differences between the inside lane and the previously un-trafficked hard shoulder of the motorway will be significant. A consequence of this, is when the hard shoulder is first opened to traffic (e.g. during the morning rush hour), an ice hazard may exist on this lane, whilst the other lanes remain above freezing. There is a need to better understand, and monitor, these differences in temperature so that it can be incorporated into the winter maintenance strategy used by Highways England.

This project will translate existing technology developed on previous research projects to quantify the temperature difference between motorway lanes. The data will be available in real time, using an 'internet of things' approach alerting engineers of the need to conduct gritting operations on cooler lanes. Hence, this project will not only impact on the actions of the project partners (potentially saving money on gritting operations), but will also improve the safety of the network for all road users. The project is particularly timely given the ongoing inquiry into 'all lane running' by the commons select transport committee.

The overall aim of this project is to produce a prototype decision support system that will provide information regarding the surface temperature of all motorway lanes which can be used to make efficiency savings as well as being consulted prior to opening the hard shoulder to traffic. This aim will be realised by the following objectives:
1. Installation of transects of networked low-cost sensors across motorway gantries, providing surface temperature information across all lanes.
2. Development of a cloud based data hub to process and visualise data
3. Integration of data into existing winter maintenance / smart motorways strategies.

This short project has two key deliverables. Firstly, the project will provide tacit knowledge of temperature differences on multi-laned roads. This information can then be used inform winter maintenance strategy more generally across the network without significant further investment. Secondly, the prototype decision support system will provide detailed and reliable real-time measurements on the selected road section leading to efficiency savings for the project partner. This approach could readily be extended across the network, given the compatibility of this approach with the 'smart motorway' approach. The project will last for 7 months to cover a substantial part of the winter season (November 2016 - May 2017) and will cost in the region of £70k (£56k 80% FEC).

This project will produce for the first time a road weather information system specifically designed to measure temperature difference across a multi-laned road. Whilst just a pilot, and the bigger potential impacts are longer term, this project has a number of outcomes for Highways England:

1. Tacit knowledge regarding temperature variations on different lanes of the motorway.
2. Indicative cost savings from business as usual by using one gritter instead of two on wide motorway sections on marginal nights.
3. Quantification of the safety related issues in opening the hard shoulder on marginal nights.
4. Build a business case to inform asset replacement strategies (i.e. bigger sensor networks, refined outstation networks, new generation of gritters to deal with widened motorways)

The project is also designed to maximise exposure to both the concept of this project and broader applications of the technology. The trade shows identified will ensure UK sector-wide awareness of the work and thus potential impacts are likely away from the project in local authorities and other national road agencies.

Other key stakeholders are taxpayers and users of the motorway network benefiting from the improved use of resources and a safer network to travel on in winter respectively.