Police in Glen Waverley and Clayton have been out in force to curb pedestrians who risk their lives by not crossing at the lights or ignoring them completely.

Their increased presence on the city's footpaths comes as new figures show a 64 per cent increase in serious-injury collisions with pedestrians in Monash from 2010 to 2011.

Twenty-three pedestrians were admitted to hospital last year due to serious injuries as a result of a collision. The statistics do not take into account minor injuries.

In a recent operation on Kingsway in Glen Waverley, police were shocked to catch about 50 people jaywalking within several hours.

The elderly population was highly represented in the figures.

Senior Sergeant Diane Wilson of the Glen Waverley police said officers had issued warnings but would soon start handing out fines.

"I think that's the only way to get the message in," she said. "The aim is to educate people about the dangers of jaywalking. We don't want anyone else getting hurt."

Clayton police are also cracking down on the number of jaywalkers flouting the law.

Senior Sergeant Geoff Hamilton said police would have zero tolerance in the suburb's main shopping strip.

"With the volume of traffic and the large trucks that travel up and down Clayton road, a lot of people have been running the gauntlet. They're openly doing it in front of police presence and that is landing lots of people with fines."

But police in Clayton also have the added job of stopping impatient pedestrians risking their lives and ducking under the boom gates.

"The concern with the crossing is that people lift the boom gates and they become like sheep one after another," Senior Sergeant Hamilton said.

"An express train is going to come through and people are not going to be as aware. It's just straight-out blatant danger."

Pedestrians risk being fined $61 for not crossing at the lights at the appropriate time and $299 for ducking under boom gates.

Senior Sergeant Wilson had a message for impatient pedestrians. "Don't do it," she said. "Look to where the pedestrian crossings are and use them correctly."