Bizarre reason you might see gritters during UK heatwave

Gritters are a familiar sight in January. In the middle of a record-breaking June heatwave, less so – but if you spot one on your commute this week, don't be confused. There's a very good reason they're out. 

The AA has warned that road surfaces can soften and become sticky under extreme heat, with heavy traffic capable of causing them to rut in some places.  

In response, some councils have already begun deploying gritters, not to spread salt, but crushed stone, to protect the tarmac and maintain grip for drivers. 

Asphalt surfaces can begin to melt when road surface temperatures hit 50°C. This threshold can be reached even when air temperatures are much lower, as road surfaces absorb and retain heat during the day. 

With forecasters warning that temperatures could hit 35°C in London and above 30°C across most of southern England this week, road surfaces in the most exposed areas could reach these temperatures.  

The crushed stone spread by gritters creates a protective layer that helps prevent surface damage while also providing extra grip for vehicles travelling over softened tarmac. 

It's not just the roads that drivers need to think about this week. The RAC has urged drivers whose vehicles don't have effective air conditioning to seriously consider postponing any non-essential journeys, warning there could be a record number of breakdowns. 

If you do need to drive, keep your speed down on roads that look or feel uneven, give extra space to vehicles ahead, and check your tyres – heat accelerates pressure build-up and a tyre blowout at speed is far more likely in extreme temperatures.