What’s the reason for the area marked in red and white along the centre of this road?

Explanation: Areas of 'hatched markings' such as these separate traffic streams that could be a danger to each other. They're often seen on bends or where the road becomes narrow. If the area is bordered by a solid white line, you mustn't enter it except in an emergency.

Category: Road and traffic signs

References: The Official DVSA Guide to Driving: Section 6, Highway Code: Rule 130, Highway Code: Page 114, Know Your Traffic Signs: Page 64