Officers were called to Lampits Hill shortly after 3pm today, Sunday 26 February, to reports of a collision involving a motorcycle and a bus.
The motorcyclist has been taken to hospital with serious injuries.
The road is closed in both directions, and we expect that closure to be in place for the next few hours.
Police need anyone who witnessed the incident or who has dashcam, doorbell or mobile phone footage of it to get in touch.
Do you have any information?
If you have any information, CCTV, dash cam or other footage in relation to this incident, then please get in contact with them by calling 101.
Make an anonymous report
If you would like to make an anonymous report you can contact independent charity Crimestoppers, by visiting their website or by calling 0800 555 111.
Please quote incident 697 of 26 February when providing any information to make sure it gets to the right person as quickly as possible.