New Yorkers should watch the carpool lanes closely. Although DOT calls the lanes a success, the addition of 8 HOV miles last year to the original 12 has so far produced relatively weak usage growth. Since the extension, east bound per-mile use of the HOV lanes during rush hour has fallen from 83.3 vehicles to 59.5 vehicles. Per-mile use of the HOV lanes could plummet further after the next extensions.

DOT and elected officials should give these lanes time to prove their effectiveness in creating carpools and holding down roadway demand before embarking on more carpool lane projects. This may be difficult to do, since, carpool restrictions notwithstanding, adding capacity to highways usually induces more driving. DOT is interested in adding HOV lanes to the Staten Island Expressway, and, as part of its LITP 2000 program, has mapped a network of new L.I. HOV lanes on the Northern State, Southern State and Meadowbrook Parkways.