The Aug. 14 front-page story "Tie-Ups as Predictable as the Tides" asserts that summer congestion on the Bay Bridge is "inevitable." Not true.

Variable toll rates could provide a free flow on summer holidays on routes to the coast just as they provide free-flow traffic in peak hours on the 91-Express Lanes in Los Angeles and on reversible lanes on I-15 in southern California, on highway 407 in Toronto and on several bridges in Lee County, Fla. On the autoroutes north of Paris, variable toll rates have been used for nearly 10 years to balance the flow of holiday and weekend traffic.

What generates the backups is not high seasonal demand but a rigid bureaucratic adherence to exactly the same toll rates regardless of the demand-supply balance. Many industries experience strong seasonal demand but don't have vast queues and customer aggravation like our roads. For example, ski-area hotels pitch their prices higher when there is snow and lower in the summer, managing to efficiently use their facilities year round without having great lines at their doors.

To their credit, the Maryland Department of Transportation and the U.S. Department of Transportation have recently initiated professional studies of variable toll rates on a number of major road facilities in the state, including the Bay Bridge. It would be possible to ensure free flow by raising all tolls during times of high demand and lowering them when demand is weak. This will encourage some people to shift the time of their trips or forgo them and allow others a more comfortable journey.

If this is too radical, a single lane in the peak direction could be designated a toll express lane for the exclusive use of those who pay a premium toll rate, and other lanes would remain low toll and low level of service as now.