Investigations into the collision between a motorbike and bus require officers to have full access to the road.
Diversions have been arranged by Traffic & Highway Services for the duration of the closure, although it is not yet known how long the inspection will take.
Bus routes are also being diverted.
Police are continuing to investigate the collision and would like to speak to any witnesses.
Anyone with information is asked to contact the police station on 222 222 or Crimestoppers, anonymously, on 0800 555 111.
The 18-year-old motorbike rider died following the collision. No-one else was injured.