Drivers have been warned to keep their eyes on the road during Friday morning's solar eclipse, which will take place in the morning rush hour.

Unlike the 1999 eclipse, this one won't involve the sun being completely blotted out from anywhere in the UK. Depending on where you are between 84 percent (in London) and 97 percent (in Lerwick in the Shetland Isles) of the sun's disc will be covered.

That's enough to reduce the light level, at a time of day when there will be lots of people on the roads. It sounds like a good day to ride to work a bit earlier or a bit later and avoid yet another excuse for drivers not to see you.

In London the eclipse starts at 8.24am, reaches its maximum extent at 9.31am, and ends at 10.41am. In Edinburgh, the eclipse starts at 8.30am and peaks at 9.35 am.

Experts from the Royal Astronomical Society and the Society for Popular Astronomy, said: "Unlike every other eclipse of any size, this one takes place right in the middle of the rush hour. It's not the best time from a safety point of view."

The Highways Agency is therefore warning people to drive carefully.

"Safety is a top priority. As always, we advise road users to drive carefully, adjusting their driving according to weather and road conditions and during the eclipse we’d ask them to do the same,” said a Highways Agency spokesperson.

The good old British weather might mean the eclipse won't be visible anyway.

Helen Roberts of the Met Office told the Bristol Post that it was too early to say for sure, but it is very unlikely the phenomenon will be visible.

She said: "In forecasting terms it is still quite far ahead.

"But what we can say at the moment is it looks like the whole of the UK will by under some cloud cover.

"There are likely to be breaks in the cloud, but it is really difficult to say where these will be at this point in time."