OCCASIONALLY on the way to work, I see people in wheelchairs working their way south along the sidewalk of Sand Point Way. When they reach 41st Avenue Northeast, the sidewalk ends. These people then wheel themselves into Sand Point's rush-hour traffic and travel down the street until the sidewalk resumes a block later

Officials should know that disabled people live in the nearby Burke Gilman Place's "affordable" housing, which was built on city land. And officials should know that the sidewalk ends. But, not yet competent with sidewalks, they are on to light rail, a megaproject.

Public "megaprojects" fail with amazing consistency. The RAND Corporation, a major research institute, studied 52 such projects costing an average of $2.4 billion each. These projects were plagued by cost overruns and delays and about half performed less successfully than intended. Rand's study, the WPPSS fiasco, and Denver International Airport strongly imply that massive public works are prone to overly optimistic planning and duplicity.

The Regional Transit Plan's (RTP) proposed light-rail project exemplifies how wishful thinking leads to ineffective and unnecessarily expensive public projects. Even though we want everyone else to take the train, the RTP won't alleviate congestion. It will lure us from more-effective traffic-management strategies. Traffic congestion is an important challenge and we probably will spend large sums to deal with it. But we will sorely regret devoting resources to a light-rail system

Although more than $20 billion was spent to build and expand rail systems in 14 cities during the 1980s, the number of people using rail to get to work fell in all but one. Los Angeles, Portland, San Francisco and Washington, D.C., have expensive rail systems but have not appreciably diminished congestion. More broadly, trips on public transit (of which light rail is only a fraction) actually declined from 9 percent of overall trips in 1970 to just 5.3 percent in 1990.

Light rail is unpopular because, for most people, it is slower and less-convenient than driving. On average, a trip that includes a ride on light rail is half as fast as a trip by car because getting to the station, waiting for a train, transferring to and from buses, and making station stops take lots of time. Rail lacks flexibility, rarely going where people want to go. Rush-hour travel between the suburbs and downtown, the type of commute rail handles best, is declining in importance. Moreover, people often make side trips to shop, exercise, or take children to school. These trips are far less convenient because tracks are rarely laid where people want to go.

According to the Regional Transit Authority's own figures, the $6.7 billion RTP will add a mere 37,000 daily rides to public transit. This is far less than 1 percent of all commutes. And most of these rail riders are people who now use buses. Instead of paying the estimated $360,000 per new transit rider, we could pay 220,000 people $2000 per year for 15 years to bike to work. Biking, like transit, is a healthy, nonpolluting method of travel.

Mass transit fails because, under current arrangements, drivers can ignore the congestion they impose on others. Even with traffic delays, automobiles offer quick, comfortable, convenient transportation for most people. Many women view their car as "a personal security device." The time we waste sitting in traffic is outweighed by these advantages. Public transit fails by comparison.

Congestion toll pricing, charging drivers a fee that rises and falls depending on how heavily the road is used, is a more-effective traffic-management strategy. Tolls make better use of existing roadways by spreading traffic more evenly over the day, encouraging carpooling and biking, and making mass transit more attractive. Tolls reduce the need for costly road expansions or rail systems. They also save time and gas while reducing pollution.

Start by placing tolls at major congestion points such as the Evergreen Point Floating Bridge and the Ship Canal Bridge. Automated Vehicle Identification and Electronic Toll Collection systems, already used in Oklahoma, Norway and Texas, eliminate backups at toll booths. Tolls would be higher during rush hour and low or nonexistent when few cars are on the road.

Ideally, our taxes will fall as tolls are used to finance road repairs and improvements. But even if taxes don't fall, new, congestion tolls are preferable to paying twice for the RTP: once, building light rail and buying buses, and again building roads to handle the vast increase in traffic that the RTP will do nothing about.

Ordinary citizens rarely analyze complex policy proposals. Work, family and friends trump people's interest in policy analysis. But public officials have a duty to choose wisely. Even if well-intentioned, their myopic fixation on light rail will lead to a project that is expensive and seldom alleviates congestion.

Our region is blessed with a highly educated and civic-minded populace, hi-tech businesses, and past public-works successes. But these blessings do not change human nature or repeal economic principles. Even with large subsidies and good intentions, light rail won't work as promised. Until we try congestion tolls it is irresponsible to commit to light rail.