Westminster Council's application for a judicial review has been dismissed and the Kennington residents' application for permission to apply for judicial review has been refused.
London's mayor, Ken Livingstone, said: "We are happy that our entire approach to the introduction of congestion charging, which has involved an unprecedented level of consultation, has been vindicated."
The six-day hearing cost £3 million.
Councillor Kit Malthouse, deputy leader of conservative-led Westminster Council, said "We question whether Britain's first congestion charge should be introduced in a complex city such as London."
However, the scheme will likely be the impetus for further charges in city centres across Britain.
Congestion charging in central London is scheduled to start on 17th February 2003.
Livingston's Transport For London agency estimates traffic in central London will reduce by 10-15 percent.
"This will help essential journeys (such as those by delivery vehicles) to be quicker and more reliable. It will also free up the roads, give pedestrians and cyclists a better deal and help vehicles making key journeys to move around the capital much more quickly and with more reliable journey times."
A spokesperson for the London Cycling Campaign said congestion charging would lead to "less congestion, less traffic, less pollution and more people cycling, all of which will make London a more pleasant and healthy place to live."
Predictably, CTC also welcomed the High Court's decision. Richard Thomas, Campaigns and Policy (Acting) Manager said: "The decision is good for Londoners and good for those using cycles to reach work, school and colleges, and leisure outlets. It is good for anyone thinking of cycling to reach destinations just a short distance away but too concerned about traffic dangers to use their bike. Conditions for cycling will improve if traffic is reduced and we hope other cities will follow London's lead."
However, motoring organisations are less enamoured of the green light given to Livingstone's congestion charges:
John Lewis, director general of the British Vehicle Rental and Leasing Association, believes Livingtone's scheme is flawed.
"[Congestion charging] will be severely damaging, especially to rental companies for whom Central London will now become a desert. That has obvious implications on employment in the congestion charging zone and our members won't be the only ones pulling out. Other businesses are sure to follow.
"For leasing businesses the result will be increased administration and cost as they will have to handle fines for non-payment by their customers' drivers. These costs will inevitably have to be passed back to the customer.
"We have deep reservations about the scheme. It is being rushed in far too quickly and is based on old number plate reading technology with a computer based system to match number plates to pre-purchased tickets. I have yet to see a publicly funded computer system that was delivered on time or that worked properly from day one.
"But don't get me wrong. The BVRLA fully recognises the need to reduce congestion in our major cities and that means a charging scheme. But for London, not this one, not now. Any scheme has to have electronic charging at point of entry, similar to that used on the Dartford River Crossing for many years. That means it could be a flexible, electronic system and not one based on buying a ticket on each occasion for a specific vehicle. Fleet discounts and exceptions for various professions, taxis and emergency vehicles could all be taken care of simply and cheaply and not through the horrendous jumble of the overly-complex, proposed scheme.
"Our one hope is that other cities will recognise the appalling complexities of Ken Livingstone's scheme and opt for a more practical and sensible scheme."