Traffic is currently at a standstill on SH3 just outside of Stratford.
A police spokeswoman says police were notified of a car having caught fire on the Midhirst bridge at 7.30pm this evening.
The car's occupants are all out of the car and are uninjured, however the road is currently blocked.
Police and the fire brigade are currently at the scene.
The New Zealand Transport Agency (NZTA) advises motorists that delays are possible.