Report on the suitability of High Occupancy Vehicle Lanes in the Greater Vancouver Regional District

Transport Action BC

by Ian Fisher

May 1997

Executive summary

High Occupancy Vehicle (HOV) lanes have attracted considerable attention as a potential strategy for addressing transportation problems in Greater Vancouver. They are a component of regional and provincial transportation plans with one facility having just opened (Barnet-Hastings) and another being under construction (Trans-Canada Highway). However, a review of North American HOV lane experience indicates that HOV lanes can contribute to longer commutes, reduced transit ridership, dispersed land use and greater vehicle travel. All of these results run counter to the goals of a compact, transit-oriented region as espoused in the Livable Region Strategic Plan. As a result, devoting resources currently allocated to HOV lanes to transit improvements would appear to be a better approach, especially since there is currently a deficit situation with regards to transit investment.

Table of Contents

Executive summary click here

Introduction click here

Background click here

Major issues surrounding HOV lanes click here

Conclusions click here

References click here

Introduction

High Occupancy Vehicle (HOV) lanes have become a popular form of roadway capacity improvement in North America over the past two decades. In 1992 there were 540 km of HOV lanes in 40 projects on separate rights-of-way or within freeway rights-of-way in 20 metropolitan areas in North America (Turnbull and Christiansen 1992.) HOV lanes are designed to provide high occupancy vehicles with a faster, more reliable journey time than is enjoyed by single occupancy vehicles travelling in paralleling general purpose lanes. While many early HOV lanes were for the exclusive use of buses, the definition of an HOV has become much broader in later years with many jurisdictions permitting HOV lane use by car pools of as few as two or more persons per vehicle. The flexibility of defining what constitutes an HOV, and the inherent ease with which roadway lanes can be converted to and from HOV status, can be seen as both advantages and disadvantages of HOV lanes. This report critically discusses the general suitability of HOV lanes in Greater Vancouver based on experience both within the region and elsewhere.

Background

Policy framework

Livable Region Strategic Plan

The Livable Region Strategic Plan sets out the following as transportation policies relevant to HOV lanes:

  • to plan and implement a transit-oriented and automobile restrained transportation system for the region based on intermediate capacity transit facilities (including light rail transit, SkyTrain and high capacity busways) within the identified corridors;
  • to assign priority for increased roadway capacities first to high occupancy vehicles, goods movements, inter-regional movements and then single-occupant automobiles.

These policies were adopted with the GVRD Board's adoption of the Transport 2021 Long-Range and Medium-Range Plans. (GVRD 1995)

Transport 2021

Transport 2021 (1993a) enters into further detail on a proposed policy for HOV lanes and recommends that HOV lanes be implemented in the following six major corridors:

  • Barnet-Hastings - Northeast Sector to Boundary Road;
  • Lougheed corridor - Highway 7 to Trans-Canada Highway;
  • Trans-Canada Highway and Grandview Highway corridor - Cape Horn Interchange to Clark Drive;
  • Trans-Canada Highway corridor - 200 Street to the Cape Horn Interchange
  • Across the Fraser River at or in the vicinity of a new river crossing between Maple Ridge and Surrey.
  • Across the North Arm of the Fraser River at or in the vicinity of the Alex Fraser Bridge-Queensborough Bridge corridor.

Only the first project listed, the Barnet-Hastings People-Moving Project, was identified as a priority for early implementation (Transport 2021 1993b).

Of key importance is that Transport 2021 recommends that HOV facilities be created from existing traffic or parking lanes wherever possible and that the creation of HOV facilities may include a time penalty for other road users. It is also proposed that road space be allocated based on people-carrying capacity rather than vehicle carrying capacity; and that governments should take into account the number of passengers per vehicle rather than simply the number of seats when allocating road space.

Going Places

The provincial government has committed itself to the creation of a system of HOV lanes in Greater Vancouver in its Going Places transportation plan (BC Transportation Financing Authority 1995). This plan acknowledges that a complete HOV network is necessary, otherwise congestion may simply be shifted from one location to another. The Ministry of Transportation and Highways is currently developing an HOV system plan.

Definitions

To aid in the discussion of HOV lanes, a familiarity with some of the major terms used to describe them is useful. These definitions are largely based on those in Fuhs (1993).

High-occupancy vehicle (HOV) lane. A preferential lane that is reserved for the use of high-occupancy vehicles. Definitions of high-occupancy vehicle vary widely according to jurisdiction, location and situation and can range from including any vehicle carrying two or more people (2+) to including buses only (creating a bus lane).

HOV lanes can operate in the same direction as normal traffic, creating a concurrent-flow lane; or in the opposite direction as a contraflow lane. In Greater Vancouver, the new HOV lanes on the Barnet Highway serve as an example of a concurrent-flow facility. The rush hour operation of the George Massey Tunnel, with three lanes in the peak direction and one lane in the off-peak direction, serves as an example of a contraflow application, although the contraflow lane is not limited to HOV's. In some locations reversible-flow lanes are used to provide additional capacity in the peak direction, as with the middle lane on the Lion's Gate Bridge or the Express Lanes on I-5 on the north side of downtown Seattle.

Queue bypasses provide a bypass for HOVs around bottlenecks such as congested ramps, freeway ramp meters and toll plazas. They are numerically the most common form of HOV lane in North America with over 950 ramp meter bypasses in operation in 1990 (Fuhs 1993).

North American experience with HOV lanes

This section provides some real world examples of HOV lane successes and drawbacks. The first project discussed, the Lincoln Tunnel approach HOV lane in New Jersey, seems an unqualified success while the Seattle and Vancouver experiences presented later are less conclusive and so are illustrative of the challenges of HOV lane planning and operation.

Lincoln Tunnel

No doubt the most utilised HOV lane on the continent is that on Route 495 leading to the Lincoln Tunnel, connecting New Jersey to Manhattan. This 4 km long counter-flow lane is open to buses only and carries over 30,000 people per hour while saving passengers up to 20 minutes of travel time (Fuhs 1993). For comparison, the busiest line on the New York subway system carries 50,000 riders in the peak hour under the East River at 53rd Street while Vancouver's SkyTrain handles a maximum of about 7,000 passengers per hour into downtown (Parkinson and Fisher 1996).

However, most HOV lanes cannot hope to reach the levels of traffic on the Route 495 lanes given the lack of highly concentrated bus transit demand corridors in most North American cities. As a result, HOV lanes elsewhere are open to a wider range of vehicles with fewer occupants per vehicle on average. Most HOV lanes in the U.S. have an occupancy requirement of 2 or more persons per vehicle (2+), although a significant number require three or more persons per vehicle (3+) (Fuhs 1993).

HOV lanes in Seattle

A partially successful example of an HOV facility with a minimum auto occupancy of two people is on I-5 north of Seattle. At NE 145th St., the HOV lanes carry 48 percent (5,268 people per hour) of the people travelling in the peak direction in only 21 percent of the vehicles (see Figure 1). The HOV lane on State Route 520, also in the Seattle area, is limited to vehicles with three or more occupants and is even more effective, carrying 42 percent of commuters in only 6 percent of the vehicles (Washington State Department of Transportation 1995). One study suggests that the Seattle HOV system reduced congestion by between 6 and 35 percent in the 1984-89 period (McMullen and Gut 1992).

Figure 1 Vehicle and people carried according to lane on I-5 at NE 145th St., Seattle, Washington (Source: Washington State Department of Transportation 1995).

Results of reducing HOV occupancy requirements in Seattle

The Seattle HOV lanes also provide a useful study of the effects of reducing the HOV lane occupancy requirement from 3+ to 2+. The I-5 HOV lanes in north Seattle were opened in 1983 with a 3+ requirement but political pressure within the state legislature in the early 1990s lead to the passage of a measure lowering the Seattle area HOV designation from 3+ to 2+. However, on the advice of the Washington State Department of Transportation (WSDOT), the governor vetoed the measure. WSDOT, in a bid to maintain control of HOV designations, subsequently initiated a 6 month trial of the reduced occupancy requirement (Dues 1993). The reduced occupancy requirement was well received by the public, being supported by 92% of motorists, 83% of carpoolers but only 39% of bus riders. Operationally, the change in the occupancy requirement brought about the following effects (from Ulberg et al. 1992):

  • Bus ridership in the corridor, which had been increasing for three years, levelled off.
  • Bus schedule reliability declined.
  • Travel times in the northbound general purpose traffic lanes increased by up to 25%.
  • Three person carpools fell from 4% of all traffic to 1% while two person carpools initially increased then declined to near original levels. Overall automobile occupancy levels remained at 1.2 persons per vehicle.
  • The number of vehicles and persons using the highway overall increased.
  • Peak hour volumes on the HOV lanes approached a maximum desirable capacity of 1,500 vehicles per hour, resulting in daily violations of the WSDOT HOV lane travel time reliability standard from about 4 to 6 p.m. With a 3+ designation, free-flow conditions in the HOV lanes were maintained with maximum vehicle volumes of 500-600 in the peak hour.

Ulberg et al. (1992) conclude that the reduction in the HOV lane occupancy requirement produced ambiguous results in some areas but at the overall cost of compromising many policy objectives for HOV lane performance. They suggest that the development and use of a specific performance standard, readily understandable by the public, be pursued. However, it appears that the pre-existing performance standards were retained as a policy adopted on August 20, 1991 remains in effect. The key statement on travel times and reliability in the policy is that, "HOV lane vehicles should maintain or exceed an average speed of 45 mph or greater at least 90% of the times that they use that lane during the peak hour (measured for a consecutive six-month period) (Washington State Department of Transportation 1992). While this policy appears quite clear, it likely not being met as the 2+ occupancy requirement remains in effect.

A 1993 estimate by WSDOT projected that $1.7 billion would be required to add the 292 miles of HOV lanes needed to complete the Puget Sound HOV network (Washington State Department of Transportation 1993).

Barnet-Hastings HOV facility

The $105 million Barnet-Hastings HOV project, opened in September 1996, is the first facility in Greater Vancouver built expressly for high-occupancy vehicles other than just buses. Other HOV facilities in the region were generally constructed for bus use only and have relatively restrictive requirements, such as permitting buses and vanpools but not carpools. HOV lanes on the Barnet-Hastings corridor operate with a 2+ occupancy requirement and, unlike HOV lanes in Seattle, are open to general-purpose traffic except in the peak direction during peak periods. Ironically, the Barnet-Hastings HOV facility effectively competes with the $180 million West Coast Express commuter rail service opened just under a year previously.

The Ministry of Transportation and Highways has not been forthcoming in providing information of the HOV lanes but a summary of a December 1996 report has been reported in the local press (Bohn 1997). While the number of vehicles carrying more than one rider in the morning peak increased by almost three-fold, from 600 to nearly 1,000, the number of single-occupant vehicles increased 46% to 5,200. Single-occupant vehicles are saving up to 10 minutes from their westbound trip while buses realise only a three or four minute saving. It also appears that former bus riders are switching to private automobiles with an 8% decline in bus ridership reported since the opening.

Major issues surrounding HOV lanes

The case studies given above provide an introduction to some of the potential successes and pitfalls of HOV lanes. Some other issues surrounding HOV lanes and their appropriateness to Greater Vancouver and the Livable Region Strategic Plan are presented below.

HOV lanes lead to increased SOV capacity

HOV lanes on North American freeways have been created almost universally by adding a new travel lane rather than by converting an existing lane to HOV operation (Fuhs 1993). The implication of this practice is that the construction of HOV facilities inevitably increases the capacity of the original road lanes for single-occupancy vehicles (SOVs) by diverting HOVs to the new lanes. Short run travel time savings are thus often realised by SOV drivers following HOV lane opening. However, vehicle speeds in mixed-flow lanes will eventually return to their original levels due to the effects of latent demand, shifts from parallel routes and induced travel (Johnston and Ceerla 1996).

Take-a-lane projects have not been successful

Two American attempts at converting general-purpose lanes ("take-a-lane") to HOV lanes met with failure. The first involved creating HOV lanes from existing lanes on the Santa Monica freeway in Los Angeles in 1976. The HOV lanes, while deemed operationally successful on the basis of throughput, transit ridership and air quality, were opened to general traffic after only a few weeks of operation due to vociferous protests from motorists. A similar situation was played out in 1992 when HOV lanes were created along the Dulles Toll Road, outside Washington DC. In this case new lanes were being constructed along the road and there was a strong sense that they should be designated for HOV use. However, the Virginia Commonwealth Transportation Board progressively opened the HOV lanes to general traffic in order to compensate for construction-related delays. Eventually, the entire HOV facility was available for general traffic with congestion going from a level of service "F" to free-flow conditions. Traffic increased as commuters switched from parallel routes. After several weeks of unrestricted access to the HOV lanes, HOV lane restrictions were introduced the Tuesday after Labour Day. The timing of this change was disastrous, coming on one of the worst traffic days of the year and during U.S. congressional election campaigns. The future of the HOV lanes thus became an election issue and after only a month of operation the lane was opened to general traffic despite a rapid increase in the carpooling rate (Stowers 1994). The Santa Monica and Dulles examples provide clear indications that, once lanes are available to general traffic, converting them to HOV lanes is at least contentious and most likely politically not viable.

Occupancy requirements

The "HOV" dilemma

The setting of HOV lane occupancy requirements is a trade-off between "empty lane syndrome", when motorists feel the lane is not being used, due to a high occupancy requirement, and the creation of congested conditions and unreliable travel times due to an excessively low occupancy requirement. Unfortunately, as the evidence from Seattle presented above demonstrates, in some cases there may be no happy ground between a 3+ requirement and empty lane syndrome, and a 2+ requirement and congestion. The threshold of perception of empty lane syndrome varies from place to place but is reported to be between 400 and 450 vehicles per hour in Seattle but up to 750 vehicles per hour in southern California. Since HOV lane operation begins to deteriorate at 1,000 vehicles per hour, with 1,500 vehicles per hour being a maximum desirable capacity (Fuhs 1993), there is little margin for error in setting occupancy requirements when the results of changing from 3+ to 2+ are so dramatic.

Occupancy requirements tend to drop, not increase

While increasing the occupancy requirement is posited as a means for addressing HOV lane congestion, only one North American HOV facility, the Katy Transitway in Houston, has had its occupancy requirement raised. The bulk of occupancy requirement changes have, in fact, been reductions (Fuhs 1993). In practice, disgruntled motorists may see the raising of occupancy requirements as tantamount to the take-a-lane HOV schemes discussed above. This is particularly true since average automobile occupancies are in decline with a 15% decline in carpooling recorded in the GVRD from 1985 to 1994 (Rock and Krajczar 1997).

Effects on land use

HOV lanes encourage sprawl

The general effects on land use and travel patterns described in the literature are not consistent with regional goals of encouraging proximity between residence and workplace. HOV lanes, by increasing travel speeds for both HOVs and other traffic, contribute to long-distance commuting. Extended commuting ranges in turn lead to the encouragement of sprawling single-family subdivisions on the periphery of the region (Johnston and Ceerla 1996). Short-term increases in travel speed are thus negated in the longer term as land use patterns adapt to take advantage of the HOV facility. Unfortunately, the narrow simulations used to justify HOV lane construction rarely look far enough ahead for this to be apparent. Johnston and Ceerla modelled the effects of adding HOV lanes, introducing light rail transit, and of creating transit-oriented developments in the Sacramento, California region. They determined that HOV projects would increase vehicle miles travelled (VMT) while investments in light rail transit and transit-oriented development would both reduce VMT. Intensification of development is not a reason given for HOV lane construction in the literature, as is commonly the case for fixed-link transit improvements.

The transit alternative

As suggested by the eight percent reduction in transit ridership associated with the opening of the Barnet-Hastings HOV lanes, HOV lanes can act against regional goals of encouraging greater use of transit. The modelling undertaken by Johnston and Ceerla (1996) also supports such a conclusion. They cite a study demonstrating that the construction of an HOV lane on I-580 in the San Francisco Bay Area would lead to an 8% decrease in BART riders and a 2% decrease in bus ridership. Reductions in transit ridership in Greater Vancouver could also be significant, particularly since the Trans-Canada Highway HOV lanes now under construction parallel both the SkyTrain and the proposed Broadway-Lougheed light rail transit line.

Given that there is considerable latent demand for transit service in Greater Vancouver (Rock and Krajczar 1997), directing scarce transportation funds to transit improvements rather than HOV lane construction would be most consistent with adopted regional policies. This is especially true given that BC Transit's Five-Year Plan projects a shortfall of 305 buses, and $403 million in funding, over the next five years when compared with the Transport 2021 scenario (BC Transit 1997). If the underlying goal of HOV lane construction is to move more people, a better application of the funds would be to a wide range of transit priority measures identified by BC Transit. A study performed for BC Transit indicates that a $26.9 million programme of transit priority measures could save $31.3 million in transit operating costs and $156.1 million in passenger time (TransVision Consultants 1994).

Conclusions

As a people-moving investment, the effectiveness of high-occupancy vehicle lanes has come under considerable scrutiny. Most evidence suggests that an aggressive HOV policy would not support, and could in fact undermine, the travel and land use goals set out in the Livable Region Strategic Plan. As an alternative, it is proposed that transit improvements be given a higher priority then HOV lanes given that their land use and transportation effects would be more supportive of the Livable Region Strategic Plan than HOV facility expansion. In some cases HOV facilities may be a component of transit improvements (bus lanes for example) but care must be taken to ensure that the benefits of such facilities accrue primarily to the transit user and not the single-occupant vehicle.

References

BC Transit. 1997. TransAction 2002: Service Plan and Funding Strategy. (Surrey: BC Transit).

BC Transportation Financing Authority. 1995. Going Places: Transportation for British Columbians (Victoria: BC Transportation Financing Authority).

Bohn, Glenn. 1997. "Barnet Highway traffic climbs, but moves faster." The Vancouver Sun, March 31, 1997, pp. B1, B4.

Dues, William C. 1993. Letter (with attachments) to the author dated August 16, 1993 from William C. Dues, Assistant District Administrator for Program and Traffic Operations, District 1, Washington State Department of Transportation.

Fuhs, Charles H. 1993. National Highway Cooperative Research Project, Synthesis of Highway Practice 185: Preferential Lane Treatments for High Occupancy Vehicles (Washington, D.C.: Transportation Research Board).

Greater Vancouver Regional District (GVRD). 1995. Livable Region Strategic Plan (Burnaby: Greater Vancouver Regional District).

Johnston, Robert A. and Raju Ceerla. 1996. "The effects of new high-occupancy vehicle lanes on travel and emissions." Transportation Research A 30:1 35-50.

McMullen, B. Starr and Thomas Gut. 1992. "HOV Lane Effectiveness in Controlling Traffic Congestion." Transportation Quarterly 46:3 429-434.

Parkinson, Tom and Ian Fisher. 1996. Transit Cooperative Research Project, TCRP Report 13: Rail Transit Capacity (Washington, D.C.: Transportation Research Board).

Rock, Clive and Karoly Krajczar. 1997. "Results of the 1994 Trip Diary Survey: Key Changes in Daily Travel Behaviour 1985-1994 (memo dated January 9, 1997)." (Burnaby: Greater Vancouver Regional District).

Stowers, Joseph R. 1994. "HOV Lessons from the Dulles Toll Road." TR News no. 170, January-February 1994, pp. 5-9.

Transport 2021. 1993a. A Long-Range Transportation Plan for Greater Vancouver (Burnaby: Transport 2021).

Transport 2021. 1993b. Interim Highway Improvements. (Burnaby: Transport 2021).

TransVision Consultants. 1994. Transit Priority: Programs that Put People First. (Surrey: BC Transit).

Turnbull, Katherhine F. and Dennis Christiansen. 1992. "HOV Lessons." Civil Engineering, September 1997, pp. 74-75.

Ulberg, Cy, Gary Farnworth, Graciela Etchart (Washington State Transportation Centre, University of Washington); Katherine F. Turnbull, Russell H. Henk, David L. Schrank (Texas Transportation Institute, Texas A&M University). 1992. I-5 North High-Occupancy Vehicle Lane 2+ Occupancy Requirement Demonstration Evaluation. (Olympia: Washington State Department of Transportation).

Washington State Department of Transportation. 1992 Washington State Freeway HOV System Policy: Executive Summary (Olympia: Washington State Department of Transportation).

Washington State Department of Transportation. 1993 Answers for People on the Move: The Puget Sound HOV System (Seattle: Washington State Department of Transportation).

Washington State Department of Transportation. 1995 HOV it Your Way (Seattle: Washington State Department of Transportation).

For another paper on this subject, prepared for the Chesapeake Bay Foundation, follow this link.

Ian Fisher
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