Traffic congestion in Manhattan is a growing problem. It reduces mobility, it increases the cost of doing business, and it decreases the quality of the urban environment.

In 2003, London implemented a $10 charge to vehicles entering a designated congested area. The charge was increased to $16 in 2005, and this past February, the size of the charge area was doubled. The result has been a 15% reduction in traffic volume and a 30% increase in traffic speed. But before implementing its congestion-charging scheme, London invested over $600 million on transportation infrastructure and in the purchase of new buses to provide additional capacity for former auto travelers.

Calls for adopting the London approach are becoming louder in New York City and are the subject of lively political debates. Environmental groups advocate such pricing as the best strategy to reduce the number of private vehicles that contribute to street congestion.

Some in the business community support congestion pricing because they see traffic congestion as limiting economic growth.

Retail businesses tend to oppose congestion charges for fear of losses in revenues, arguing that congestion is a byproduct of economic and population growth. They believe what must be done to deal with this growth is to make our road and transit system more efficient and productive through real-time traffic control, better enforcement of traffic regulations, and improved transit services, rather than adding a charge to the cost of private vehicle travel.

Those not from Manhattan argue about equity issues and take the view that New York City may not need the same prescription as London.

Each side of the congestion debate argues from its own conviction and from different perspectives on this vital urban issue.

What is lacking in the current congestion pricing debate is an organized framework for sorting out the specific and complex issues that cause Manhattan’s traffic congestion problem.

So what are some of the particular factors that contribute to the congestion burden in Manhattan? Here are four key contributors that should be considered in determining the policy strategy needed for Manhattan:

(1) Traffic lanes, especially curb lanes, are often used by vehicles stopped or standing, thus creating bottleneck conditions.

(2) Cruising for customers generates half of all taxi mileage.

(3) About 30% of traffic entering Manhattan below 59th Street is going through — and not to — Manhattan. For Canal Street, through-traffic can get as high as 40%.

(4) About 10% of the traffic in Manhattan is generated by drivers cruising for a curb parking space.

Would implementing a flat congestion pricing charge to the area below 59th Street be the most effective action to solve these problems? It may go a long way to reducing congestion, but it is not an optimal strategy, for it could discourage patrons from coming into the city.

Shaping policy to address these four factors would undoubtedly yield a more equitable solution. Such a strategy would focus on improving traffic mobility through traffic engineering improvements and more efficient enforcement of curb lane regulations; developing new regulations limiting taxi cruising, and implementing congestion pricing techniques that specifically discourage both through-trips and cruising by drivers searching for a parking space.

If congestion pricing is to be proposed for trips with Manhattan destinations, a compelling reason to do so must be provided. The case for this approach is yet to be made.

Mr. Falcocchio is a professor of transportation planning and engineering and director of the Urban Intelligent Transportation Systems Center at Polytechnic University in Brooklyn.