Drivers heading north for the long weekend have had a slow start after a car caught fire at the northern end of the Sydney Harbour Tunnel, causing it to be closed in both directions.

Emergency services responded after receiving the call around 6.10pm on Friday.

Traffic inside the tunnel was at a standstill after the car caught fire shortly after 6pm. Credit:Simon Ravindran

Traffic inside the tunnel was at a standstill for about 45 minutes, with some people getting out of their cars and walking.

Paramedics on bikes were spotted cycling past cars towards the incident, but a spokeswoman for NSW Police said the 52-year-old driver had exited the vehicle and was uninjured.