One of two cars driven by intoxicated teenagers wound up crashing on its side with its 16-year-old driver abandoning the trapped occupant following a botched getaway on Wednesday night.

Police were attending a disorder event at High St Mosgiel on Wednesday around 12.15am, when they spotted two cars coming towards them.

Senior Sergeant Anthony Bond said that when Police turned around to stop the vehicles, one of the vehicles took off at speed, while the other slowed down and blocked the motorway to prevent another patrol car from going past to catch the fleeing vehicle.

Police stopped the first vehicle at Kinmont, which was occupied by two 17-year-olds.

The apparent driver underwent a breath screening test and blew 671mcg, though investigations, which including reviewing of CCTV footage it was discovered the driver and passenger had swapped seats - he was also then screened for drink-driving, Bond said.

He blew 593mcg.

The legal limit for a driver aged under 20 in New Zealand is zero.

Meanwhile, the vehicle that had fled was pursued by a Police dog vehicle and was found crashed in a culvert and rolled on to its right hand on School Rd South.

The 16-year-old driver of the vehicle had removed himself and continued to flee on foot, leaving behind a 18-year-old male trapped in the vehicle.

Hato Hone St John and Fire and Emergency NZ were called to the scene, and the 18-year-old was extricated from the vehicle and transported to hospital.

The 16-year-old was found to have a breath alcohol level of 491mcg.

The occupants of the other car were not arrested and will be referred to Youth Aid.

The occupant who blew 671mcg had his licence suspended for 28 days, and the vehicle was impounded for six months for failing to stop.

Ben Tomsett is a Multimedia Journalist for the New Zealand Herald, based in Dunedin