Bourke Street mall security upgrades complete

A multimillion dollar security upgrade at Melbourne's Bourke Street mall shopping strip is finished, more than two years after a deadly car attack that killed six pedestrians.

The popular CBD street has been fortified with 131 new steel bollards, additional CCTV cameras and a public address system, to prevent another vehicle attack like the January 2017 rampage.

Street furniture and planter boxes also provide a protective zone for pedestrians.

Victoria Police Commander Tim Hansen said the security measures will "deter, disrupt and detect those that are out to cause the most harm".

"This type of infrastructure will go a long way to preventing those types of incidents occurring again," he told reporters on Wednesday.

The security upgrades were part of a wider $52.5 million CBD package which also had works on Princes Bridge and Flinders Street Station which were completed earlier this year.

Work at other popular city sites including Federation Square, Southern Cross Station and the State Library is continuing.

In the meantime, 440 concrete temporary bollards have been placed around the city.

"We've got a changing national and international environment in terms of lone-wolf actors around what we know about terrorism," Police Minister Lisa Neville said.

"These are the sort of measures that you're seeing being put into place now across the world."