Boom gates at some of Melbourne's busiest level crossings are down for more than two-thirds of the morning peak, leaving motorists stranded in traffic for hours every day.

An analysis of the 17 level crossings identified for removal by Labor in its first budget shows motorists are stuck at boom gates for a combined 16 hours during the two-hour morning peak, causing massive disruption and costs.

Crossings on the Dandenong corridor where particularly bad. The boom gate at Koornang Road in Carnegie was found to be down for a maximum of 87 minutes between 7am and 9am, or an extraordinary 72.5 per cent of the time.

Boom gates on Clayton Road were down for 82 minutes, or 68.3 per cent of the time, while Centre Road in Clayton boom gates were down for 75 minutes, or 62.5 per cent of the morning peak.