► M6, M1, M5, M602 affected
► Will be on trial for at least a year
► No exceptions
Get ready to leave your house earlier - the Government is set to trial speed reductions on four motorways in England before October.
The M6, M1, M5, and M602 will be reduced from 70mph to 60mph sections in a bid to reduce pollution in these areas.
Why now?
The areas in question have seen higher than recommended levels of nitrogen dioxide, according to Highways England.
Nitrogen dioxide (NO2) is released from exhausts and is a pollutant linked to respiratory illnesses.
Highways England will examine the results of the trial after 12-15 months and draw conclusions from them.
Shouldn't manufacturers be in charge of reducing emissions?
Quite. Ivan Le Fevre, head of environment at Highways England told the BBC: "Ultimately the air quality challenge will be solved 'at the tailpipe' by vehicle manufacturers and changes in vehicle use.
"Until this happens we will continue our extensive programme of pioneering research and solutions."
Any specifics?
M6 - junctions 6 to 7 near Witton
M1 - junctions 33 to 34 by Rotheram
M5 - junctions 1 to 2 near Oldbury
M602 - junctions 1 to 3 by Eccles
What about electric cars?
We understand what you're getting at. Electric cars produce no nitrogen dioxide when driving along, so isn't this a bit worthless for them?
Maybe. But there are no exceptions. These lower limits are for all drivers and will be enforced 24/7. New signage will be in place too.
Science?
These trials certainly pass the smell test. Generally, the higher the car's speed, the more fuel it uses. The more fuel, the more pollution.
Of course, this changes from car to car.
Olga V Lozhkina and Vladimir N Lozhkin tested the nitrogen oxide emission rates of 13 petrol and 3 diesel cars in St Petersburg, Russia.
The cars ranged from pre-Euro 1 - Euro 5 and were tested at speeds from 10 to 120 km/h. The research showed that older cars' sweetspot of producing the least amount of nitrogen oxide was at lower speeds than newer cars.
For instance, a VAZ (Lada) 21093 without a catalytic converter produces more nitrogen oxide the faster it gets. But it's different with modern cars. A Mercedes-Benz GLA produced far fewer nasty bits, right up to 80km/h, where it produced 0 nitrogen oxide. Any faster than that and it started producing more again.
This is just one study of course. But what we're getting at is that most modern cars have a sweet spot of producing the least amount of nitrogen dioxide, and it may be lower than 70mph.