The number of people using cycle lanes in Belfast has risen by more than 50% over the past five years, according to new data compiled by the Government.
Provincewide, the numbers using a cycle route network that now extends to 700 miles was up by 25%.
In Belfast, where traffic congestion has been getting worse year by year, the number of bikes on cycle routes rose by 56%.
The figures were produced by the Department of Regional Development's cycle monitoring group for the Northern Ireland Cycle Forum, and cover the period from 2000 to 2005.
A spokesman said: "The increase in cycle usage in Belfast is encouraging, and the department is promoting this by providing appropriate infrastructure and assistance with promotional activities."
The greatest increase in Belfast was at Ormeau Bridge, where a 120% increase was detected.
Cycle Northern Ireland, a pressure group aimed at boosting cycling, said several factors were responsible for the upsurge.
It said that worsening traffic congestion and rising fuel costs and parking charges all played a part in encouraging commuters to switch to the bike.
Marketing officer Kathryn Callaghan said: "We are confident that numbers will continue to rise as even more people realise the advantages of going by bike. In the business world, workers can now benefit from tax breaks which enable them to purchase a bike through their employer free of tax and VAT, and this is proving popular."
Steven Patterson, local manager of Sustrans, which co-ordinates cycle routes, said it was delighted by the findings.
"Some parts of the National Cycle Network, such as the riverside route in Belfast have seen a 100% rise in the number of cycling trips over five years, with high satisfaction rating among users. These figures should encourage the Government to increase investment and provide quality cycle networks in all our cities, towns and villages."
Tom McClelland of local cycling campaign group Northern Ireland Cycling Initiative, said: "We are delighted with the increase in cycle usage in Belfast.
"The report demonstrates that investing in better facilities for cyclists pays off in terms of an increase in cycling.
"Cycling is environmentally friendly, fuel efficient and there are sound economic reasons why there should be more walking and cycling provision."