Section 1121 of the Act concerns use of high occupancy vehicle (HOV) lanes, allowing States to permit single-occupancy vehicles to use HOV lanes subject to payment of a toll (HOT lanes). Automatic toll collection is required. This authority is separate and independent of the Express Lanes pilot program that permits tolling of existing (but not newly created) HOV facilities.
States May Permit Use of HOV Lanes by Hybrids. The Act permits States, at their option, to allow certain low emission vehicles and energy efficient vehicles (hybrids) to use HOV facilities. A State may elect to charge no toll for these vehicles, or to charge a toll that is less than the toll charged to other single-occupancy vehicles. It remains to be seen whether States will be willing to allow toll-free use of HOT lanes by hybrids, given the adverse impact on revenues that would result.
Impact on Operations. Subsection (d) requires the State agency to limit or discontinue use of an HOV facility by single occupancy vehicles if the presence of the vehicles has "degraded" the operation of the facility. Operation of the facility is deemed "degraded" if vehicles operating on the facility are unable to maintain a defined minimum operating speed 90% of the time over a consecutive 180-day period during morning or evening weekday peak hour periods (or both). "Minimum operating speed" is defined as 45 mph on an HOV facility with a speed limit of 50 mph or greater; and not more than 10 mph below the speed limit, in the case of an HOV facility with a speed limit less than 50 mph. This provision may be troublesome to investors in such projects, since they cannot be certain that tolling will continue if use by single occupancy vehicles "degrades" the operating speeds of the HOV facility.