ITE PAPER: HOT lanes have promise

The Institute of Transp Engineers (ITE) has a task force on HOT lanes at work led by Kenneth Orski, a veteran of transp policy in Washington DC. The Orski panel is due to report around the turn of the year. Meanwhile it has had discussions with most of the leading people in the field and has commissioned several papers from experts. We have one written by Chuck Fuhs of the LA area office of Parsons Brinckerhoff an HOV lanes expert, Joe El Harake Caltrans liaison with toll projects and Bill Stockton of the Texas Transp Inst. The Fuhs trio write that there are 4 justifications for HOT:

• under-utilization of HOV lanes — empty lane syndrome

• management of heavily utilized HOV — transition HOV2+ to HOV3+

• generating revenue

• pursuit of regional air quality or roadway efficiency objectives

The latter 2 generally are a consideration in design of new lanes, but the underuse and management warrants are applicable to both new and existing HOV lanes. The writers see “two windows of opportunity” for HOT: when the HOV lanes are too empty and when they are too full.

Fuhs et al define empty as 500 vehs/lane/hr and less and full as over 1500-1800 vehs/lane/hr, with adjustments for vehicle mixes and roadway specifics. They comment: “For most HOV lanes that operate with a heavy percentage of carpools, or are forecast to have excess demand, HOT lanes may be appropriate to implement.” They suggest it may be better to start new HOV lanes as HOTs — allow toll buy-in from the start of new HOV lanes — rather than to consider a strategy of beginning without buy-in in order to introduce it later. (This is precisely the OCTA staff recommendation in the case of SR-91-West’s two HOV lanes currently under construction in Orange Co CA). Later introduction may prove “less sellable” than doing HOT right way, they suggest.

A problem in conversion from HOV2+ to HOV3+ will be the impact on the general purpose lanes — the HOV2s suddenly added to the unrestricted lanes. Fuhs et al write: “Tolling is one way of metering volumes into the HOV lane to preserve its level of service and minimize imapcts on other lanes by some of the previously eligible vehicles (HOV2s).”

They note that polls in Orange Co CA show good support for tolling new lanes and existing HOV but very low support (20%) for tolls on existing unrestricted lanes.

They say there is increasing consideration of HOT lanes during the major investment study (MIS) stage of considering alternates in major reconstruction projects. HOT lanes potential revenue makes them attractive at the MIS stage.

Eligibility — most HOT projects allow HOV3+ free and toll the others, which the Fuh paper says typically means 70% to 85% of the lane’s capacity can be sold, while 15 to 30% is taken by the HOV2+s. Allowing HOV2s free means only 10 to 50% of capacity is available for toll. Complex issues arrive when a HOV3+-free/Toll lane transitions to HOV2+, with plenty of opportunities needed between so that motorists do not get trapped when weaving is difficult.

“Future prospects for HOT lanes appear to be greatest for new projects yet to be constructed and for selective cases where sufficient capacity can be sold to generate greater use and improved management. Public attitude surveys currently suggest (that) tolling (existing) heavily utilized facilities may be difficult (politically) and has yet to be demonstrated.”

They think that generally 20 to 60% of HOT implementation cost including construction work can be supported by tolls so the potential for complete privatization of new facilities will be limited. However converting existing HOV lanes or already-funded HOV lanes to HOT will offer a “significant” revenue stream since the toll revenue will certainly exceed conversion costs.

“The greatest potential for meaningful revenue is likely to come from projects that can provide at least two HOT lanes in each direction. This is not only because more capacity can be sold but because the number of free HOVs, usually 3+ are generally a constant...”

3x2 HOT lanes within (or underneath) 2x4 unrestricted lanes have been chosen as the locally preferred alternative in a MIS for reconstruction of the LBJ I-635 in north Dallas TX (TR#16 Jun 97 p1), and 2x2 HOT lanes inside 2x4 regular lanes seem likely to be part of the longterm plan for rebuilding of I-10 Katy Fwy west of Houston TX (TR#18 Aug 97 p12). And Maryland’s MIS for widening its segment of the Washington Beltway I-495 has HOT lanes as an option.

The Fuhs group sees HOT as most attractive in “the largest cities with the most severe congestion and funding shortfalls.” (Contact Ken Orski 202 775 0311, Chuck Fuhs 714 973 4880x118)