If you are unsure exactly what a Smart Motorway is then it will probably come as a surprise to you that several of the UK’s major roads (including the M1, M6, M25 and M42) are already operating under their systems. So what are they and what do they do?
A Smart Motorway is a section of road that is monitored from a control room and the flow of traffic is improved by utilising different speed limits. During peak hours the hard shoulder is also used to provide more space for commuters. This method began on the M42 back in 2006 with promising results and has expanded since to several more motorways. The scheme falls under the banner of Active Traffic Management or ATM.
The operation has 4 main tiers that help to improve the flow of traffic, safety and environmental impact of everyday road travel. The most expansive level known as “All lane running” has variable speed limits along with full use of the hard shoulder. The other options include temporary use of the hard shoulder when congestion is at its worst and opening up all lanes across junctions.
The idea is to allow traffic to be controlled so that cars approaching sections of slow moving traffic are slowed and can avoid making any jam that much worse, whilst allowing that jam to dissipate more quickly. The system also has the advantage of being able to be run on existing roads without any need for lane widening, which saves a huge amount of cost and environmental impact.
In the time that it has been running analysis of traffic data has shown material improvements across the board. Journey reliability has improved by almost a quarter; the roads are safer with fatalities down by a half and the seriousness of injuries has been reduced. To counter the fact that the hard shoulder can be in use Emergency Refuse Stations have been set up at regular intervals (less than 2 minutes apart) to provide phones and a safe stopping place for any breakdowns or other reasons that a vehicle needs to stop. When incidents do occur lanes can be rapidly closed to allow faster access to the scene for emergency vehicles.
There are criticisms of the scheme though and they do seem to have some depth to them. The issues regarding carbon emissions are ambiguous and it’s not really known yet if there is any benefit or an increase in pollution. Environmental groups fear that they could well increase but Highways England disagrees, pointing out that a better flow of traffic should help reduce emissions and the lack of any widening work also lessens the impact. There is no clear conclusion to be reached at this stage however and it is something that will be monitored closely as the scheme gathers pace.
Another concern is regarding safety and the worry that users may well stop on the hard shoulder as they are to doing when it is actually open to fast moving cars. This isn’t considered terribly realistic as it would need a considerable gap in any traffic for the driver to be unaware and the signs that flag the additional use of the lane are very visible. Additional concerns are mainly around disabled access to refuge point phones and safety when driver or passengers may have to exit the vehicle.
On balance ATM and Smart Motorways do seem like a good thing based on known data. However the Government has made it clear that carriage widening will still be required so it’s not going to be a definitive answer to our traffic woes at this stage.