More than $1 million worth of laser beams and road-side alarms are the latest in a long line of attempts to fix one of the state's most dangerous low-hanging bridges.

The state government will spend $1.2 million on new technology, it was announced on Sunday morning, in an effort to stop trucks running into Footscray's Napier Street bridge which has been hit more than 70 times in 12 years.

Marsha Thomson and Luke Donnellan have announced new technology to help prevent bridge strikes. Credit:Scott McNaughton

But Roads Minister Luke Donnellan conceded that a suite of expensive measures at the notorious Montague Street bridge in South Melbourne have not completely stopped large vehicles from colliding with the obstacle.

The bridge strikes at Napier Street have continued despite more than 20 warning signs posted on approach roads, alerting drivers to the danger.