• Often the stated goals for HOV lanes are to reduce traffic congestion and improve air quality. Studies show that the lanes fail to meet those goals, or that the differences are statistically insignificant. TxDot usually states a more modest goal: “improving overall roadway efficiency.”
• There are over 120 HOV lanes across the U.S. Only 6 HOV lanes have been returned to mixed-flow since the late 1970s. Two of the closures were in New Jersey.

·        One report suggests that the following “characteristics are key to the success of HOV projects…

o       Metropolitan areas with more than one million people,

o       Work trips to major urban centers with 100,000 or more jobs …

o       High levels of traffic congestion.” (Turnbull, 2001)

·        A recent CalTrans survey of 3,000 California residents found that 88 percent supported carpool lanes, but 42 percent believed the lanes were underused. (Jaskevich, 2001). This persistent belief by motorists that the lanes are underused is the biggest public acceptance problem for HOV lanes.

• HOV lanes in the Seattle area tend not move much faster than the general purpose lanes. There seem to be two reasons for this: 1) drivers are uncomfortable with a big difference in speed between them and the other lanes, and 2) vehicles entering and leaving car-pool lanes must slow down to merge. (Tu, 2001)

·        Enforcing the rules on HOV lanes can be a problem, according to one source: “Highways report peak-hour violation rates of 75 percent on I-4 in Orlando and 40 percent on I-95 in Miami, a virtually complete breakdown in enforcement. Other examples of high violation rates are on HOV lanes on Virginia's I-66 (45 percent) and I-95 (55 percent), Houston's Katy Transitway (35 percent), New Jersey's I-95 (30 percent), and I-5 south of Seattle (30 percent) and north of Seattle (19 percent) [Tumbull and Hanks; Lomax and Fuhs; Farnsworth].” (From “Re-thinking HOV”)

·        A USDOT report says “There does not appear to be a consensus among transportation professionals on which criteria or measures should be used to evaluate HOV facilities.”

·        There is a small, but very vocal, anti-HOV group out there. If MoPac gets an HOV lane, these sorts of people will undoubtedly spring up in Austin. These two websites are indicative of these group’s views: http://www.users.nac.net/jmp/hov_myth.htm and http://home.earthlink.net/~malli/.

“Take-a-lane” HOV projects

It is not illegal to convert a general-use lane to HOV; however, in practice this has rarely been tried. There are two instances that are commonly discussed in the literature, the Santa Monica Freeway Diamond Lanes (1976) and the Dulles Toll Road (1992). Here are four accounts of “take-a-lane” projects.

 From “Report on the Suitability of High-Occupancy Vehicle Lanes in the Greater Vancouver Regional District” by Ian Fisher. Transport 2000 BC. May 1997. 

“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.”  

From “An Assessment of Techniques for Modelling High-Occupancy Vehicle Lanes.” by Robert B. Noland, John W. Polak and Gareth Arthur

“In 1976 the first HOV lane was introduced in Southern California along the Santa Monica freeway (Kain et al., 1992). This was a heavily congested corridor from Santa Monica to downtown Los Angeles. One lane of the freeway was converted to HOV 3+ operation (including buses) during the peak hours. The project lasted only 21 weeks due to poor planning and local opposition. This effectively eliminated the consideration of additional HOV lanes in Southern California until the mid-1980’s and, more importantly, convinced US policy makers that conversion of existing lanes to HOV lanes would not succeed (due mainly to political opposition to the short-term disruption that would be caused). Since then, all HOV lanes constructed in the US have been capacity expansions that have added lanes to existing freeway (motorway) facilities.”  

From “Re-Thinking HOV - High Occupancy Vehicle Facilities and the Public Interest” by Christopher K. Leman, Preston L. Schiller and Kristin Pauly.

“It did not take an earthquake for the Washington State Department of Transportation to convert a general purpose lane in November 1993. A lane of I-90 (9.4 lane miles) was converted westbound to 24-hour HOV (the eastbound section is scheduled to be converted in connection with a future resurfacing project). The converted lane connects with a recently constructed HOV lane running west to Seattle and cost only $100,000. Newly constructed lanes would have cost $70 million and were not scheduled until after the turn of thecentury. In the peak hour, the converted HOV lanes were carrying about 350 vehicles in 1994-considerably below the threshold that some regard as subject to "empty lane syndrome"—yet there has been little public resistance to the change. In 1994 the New Jersey Department of Transportation was successful in converting five miles of general purpose lanes on I-80 to HOV. These lanes had been constructed for HOV use but were opened up to general purpose traffic until connections were available to other HOV lanes. The conversion was eased by a long period of marketing that included highway signs informing drivers that lanes were scheduled to become HOV [Fisher, 1994.] [Ed note: The I-80 HOV lane was discontinued in 1998 after very vocal public protest.]

From “HOV Lessons from the Dulles Toll Road” by Joseph Stowers. TR News. 1994

“…To help alleviate this congestion, a decision was made to widen the toll road to six lanes, and as part of a planned area-wide HOV grid network, to dedicate the two inner lanes to HOV during peak periods. At this time, the decision was widely supported by local officials and community organizations…

“However, the lessons from the Santa Monica diamond lane debacle had not been learned. The new toll roads were first opened to all traffic, then converted to HOV operations after commuters had enjoyed free-flow conditions for a few weeks. When the HOV operations began the day after Labor Day 1992—one of the heaviest traffic days of the year—the LOS went from A to F, and opposition to HOV went from being an occasional dissent to the dominant transportation issue in the region.”

“The Effects of New High-Occupancy Vehicle Lanes on Travel and Emissions”

This article by Robert A. Johnston and Raju Ceerla essentially deals with the methodology of traffic modeling but makes several points interesting for the MoPac situation:

• They believe new HOV lanes increase VMT and emissions, especially when compared to ‘do-nothing’ or transit alternatives. New HOV lanes create new single-occupancy vehicle capacity and therefore create induced travel.

• In a theoretical model for the year 2010 based on data from the Sacramento region, the authors compared take-a-lane HOV to new construction HOV. They found that the take-a-lane option would increase VMT, total vehicle hours and vehicle hours of delay while creating a lower number of transit trips. It also increased air pollutants.
• “The CAA [Clean Air Act] also states that USDOT may not approve non-listed TCMs [transportation control measures] if they would encourage single-occupancy vehicle capacity section [179 (b)(I)(B)(viii)]. New HOV lanes always increase single-occupant vehicle capacity, compared to the do-nothing alternative because they attract some vehicles previously occupied by 2 or more persons from the mixed-flow lanes…New HOV lanes, therefore, may be legally vulnerable, even though they are listed as approvable in preceding provisions of the CAA.”

• The time savings in the general-use lanes created by new HOV lanes is usually temporary. Furthermore, new HOV lanes generally do not reduce volumes on adjacent lanes.
• The authors believe it is not sufficient to study on the changes in travel times along the freeway segments where HOV lanes have been added, as is common practice among DOTs, local governments and academics. Instead, impacts on the entire regional transportation should be examined. They also recommend studying the impacts 40 years into the future. Twenty years is a more commonly-used time frame.
• A Sacramento study of 10 HOV lane projects showed that 8.4% of the HOV users were formerly transit riders.

“New Jersey I-80 and I-287 HOV Lane Case Study.” Texas Transportation Institute, The Texas A&M University System and Parsons Brinckerhoff Quade and Douglas, Inc. Sep. 2000

Christiansen, Dennis L. “High-Occupancy Vehicle System Development in the United States.” U.S. Department of Transportation, Dec. 1990

Fisher, Ian. “Report on the Suitability of High-Occupancy Vehicle Lanes in the Greater Vancouver Regional District” Transport 2000 BC. May 1997.

Haboian, Kevin. “Integrating HOV to Enhance Operations of the Transportation System.”  Transportation Research Board.

Jaskevich, Marianne. “Mixed reviews for HOV lanes.” American City & County. Oct. 2001: 60.  

Johnston, Robert A. and Caroline J. Rodier. Automated Highways: Effects On Travel, Emissions, and Traveler Welfare.” Journal of Transportation Engineering. May-Jun. 1999.

Johnston, Robert A. and Raju Ceerla. “The Effects of New High-Occupancy Vehicle lanes on Travel and Emissions”  Transportation-Research,-Part-A:-Policy-and-Practice. 1996.

Leman, Christopher K. et. al. “Re-Thinking HOV - High Occupancy Vehicle Facilities and the Public Interest.” Chesapeake Bay Foundation. http://www.fta.dot.gov/library/planning/RETK/retk.html.

Marsh, David. “HOV lane experiment a failure - U.S. study.” Richmond Review. 21 Feb. 1996.

Noland, Robert B. et. al. “An Assessment of Techniques for Modelling High-Occupancy Vehicle Lanes.” http://www.cts.cv.ic.ac.uk/staff/wp16-noland_etal.pdf

Stockton, Wm. R. et. al. “The ABC’s of HOV: The Texas Experience.” Texas Transportation Institute, Sep. 1999

Tu, Janet I. “HOV lanes may not be fast track.” The Seattle Times. 13 Jul 2001, sec B: 2.

Turnbull, Katherine F. “8^TH International Conference on High-Occupancy Vehicle Systems” Transportation Research Circular. Jun. 1997.

Turnbull, Katherine F. “An Assessment of High Occupancy Vehicle (HOV) Facilities in North America.” U.S. Department of Transportation, Aug. 1992.

Turnbull, Katherine F. “Evolution of High-Occupancy Vehicle Facilities.” TR News May-Jun. 2001: 6-10.

Turnbull, Katherine F. and Sarah M. Hubbard, eds. “HOV Systems in a New Light: 7^th International Conference on High-Occupancy Vehicle Systems.” Transportation Research Circular. Jul. 1995