London mayor election: Green Party in transport pledge
London's Green Party mayoral candidate has pledged to cut the cost of fares and invest in public transport, if she is elected.
"We will ensure public transport is always cheaper than driving," Jenny Jones said.
The Liberal Democrats and Labour have also promised to cut fares, while the Conservatives have pledged to cut Tube delays by a further 30% by 2015.
Londoners are due to go to the polls on Thursday, 3 May.
Ms Jones said revenue would be raised through measures including a higher "gas guzzler" charge for the most polluting vehicles.
She said she would prioritise tackling road safety and air pollution if elected.
"We want to make our streets safe and that includes bringing in a default 20mph for all boroughs where they want it.
"We want to make our air clean. That's a traffic issue but it's also a health issue."
The Green Party candidate added: "At the moment air pollution in London is absolutely appalling.
"We have to do whatever we can to improve it."
She said if she became mayor, the entire fleet of London buses would be converted to low-emission hybrid, hydrogen or electric models by 2016.
Meanwhile, the Tory and Labour mayoral candidates tried to focus on policy in the aftermath of Tuesday's clash over their tax affairs on LBC radio.
Lib Dem candidate Brian Paddick said: "What voters are really interested in is what are we going to do as mayoral candidates for Londoners in the future, and yet Ken and Boris seem to just want to take lumps out of each other."
Conservative candidate Boris Johnson set out his economic manifesto, calling for more of Londoners' taxes to stay in the capital - a key election pledge.
Labour candidate Ken Livingstone set out his plans to tackle crime, saying he would appoint the capital's first ever victims' commissioner for London.