One in five pedestrian crossings at junctions in London do not give people enough time to cross the road, it has been revealed.
Figures obtained by London Assembly Lib Dems show 472 crossings do not comply with the minimum timings guidelines.
They do not provide enough time between the green light disappearing and the amber light appearing to start traffic.
Transport for London (TfL) said it would be upgrading the crossings over the next three years.
The London Lib Dems, who obtained the figures through a Freedom of Information (FOI) request, demanded urgent action to tackle the problem.
"London, out of all the UK regions, has the highest number of pedestrian road deaths and serious injuries," said the party's London Assembly member Caroline Pidgeon.
"Therefore Transport for London and the mayor have got to do something about this."
A TfL spokeswoman insisted the capital had an "excellent record on road safety".
She said from the mid 1990s to 2007 there had been a 40% drop in the number of people killed or seriously injured on London's roads.
In 2007, 1,292 people were killed or seriously injured compared with 2,136 between 1994-1998.
She also said work was already being carried out to resolve the issue.
"The vast majority - 90% - of pedestrian crossings already meet the very latest guidelines and we are working hard to upgrade the remaining sites," she said.
"All of these crossings are safe and have always provided a safe crossing time."
By the end of the financial year 2009/10, 138 crossings will be upgraded, in the following year work will begin on 100 more and finally in 2011/12, work will start on the remaining 166 sites, she said.
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