HOV Lanes Exposed

Carpool lane facts for the San Francisco Bay Area

The bottom line:

Fewer people carpool today than before carpool lanes even existed.

Carpool lane construction increases solo-drivers more than HOVs, by more than twice as much.

The facts below, all from government data, contradict the "politically correct" facade of HOV lanes. This facade was created by highway construction interests, including Caltrans, to achieve their real goal: more highway construction.

The definition of carpool is a distortion of the concept:

• 40% of carpoolers are from the same household.¹
• From a Rt. 237 questionnaire¹¹, 51% of carpoolers commute with a family member.
• Designating one passenger in a vehicle as a "High Occupancy Vehicle" is a distortion of the concept. This is Low Occupancy. Many metropolitan areas locations only allow buses and approved vans. [The I-80 freeway is 3 persons, all other Bay Area carpool lanes are 2 persons.]
• The logic behind HOV lanes is to give preferential treatment to encourage commuters to change from solodriving to carpooling. Chauffeuring the spouse to work (thus doubling the commute trip by doing two round trips daily) or the kids to school is not a logical criteria for preferential treatment.

Carpool lanes¹⁸ greatly increase solo drivers:

• Solodrivers accounted for 79% of 5769 vehicles added to Montague Expressway six years after constructing the HOV lane. This solodriver figure for San Tomas Expressway is 73% and for Rt. 237 is 63% of vehicles added to the roadway. (All vehicle counts are when HOV lanes are activated, AM+PM commute.) Rounded off, HOV lane construction added between 2 and 4 times as many solodrivers as HOVs. See detailed studies by MTS.³
• "Thousands of solo drivers are pouring onto our freeways and filling spaces vacated by carpoolers" when constructing a carpool lane, writes Gary Richards of Mercury News.⁵

Carpool lanes increase air pollution:

• Jean Roggenkamp, a transportation planner for BAAQMD, stated that "Frankly, there is no reduction in auto emissions"⁵ by constructing carpool lanes.
• HOV lane construction has never reduced automobiles, it has always increased them. Even worse, it has ALWAYS increased solodrivers and Vehicles Miles Traveled (VMT).
• The Bay Area is again in non-attainment of the Federal Clean Air Act, despite constructing 266 mile of carpool lanes.⁷
• Carpool lane construction is a solo driver incentive in disguise: new solodrivers outnumber new carpoolers by (rounded off) two to four times. This is because space is freed up in non-carpool lanes as carpoolers move over to the newly constructed lane.³
• Re-designating an existing lane as HOV would decrease air pollution. But in all cases carpool lanes are newly constructed lanes or the even worse situation of allowing HOVs to use bus lanes (the latter for the Bay Bridge). The claim that carpool lanes decrease air pollution by RIDEs and highway construction interests is blatently false. Their claim is also outrageous because the purpose of this propanda is to constuct even more highway lanes which further decreases air pollution.
• BAAQMD states that "Motor vehicles represent the largest source of air pollution in the Bay Area."¹⁶

Fewer people carpool today than before HOV lanes existed:

• In 1980 when there were no carpool lanes, 16.3% carpooled⁸ compared with 14.3%¹⁴ in 1998. This was despite constructing 266 miles of carpool lanes⁷, beginning in 1982.
  • A study by RIDES found carpooling has decreased from 16.7% to 14.3% of commuters (1993-1998).⁸
  • From census data, carpooling decreased between 1980 and 1990 in the Bay Area, from 20.5% to 15.9% of motor vehicles. As percent of commuters (including mass transit, bicycles, walkers), carpooling decreased from 16.3% to 12.9% in the same period.¹⁴
  • In Santa Clara County carpooling fell from 17% of commute trips to 12.5%¹⁵ despite constructing 115 miles of HOV lanes in that period (1982-1990), more than all other Bay Area counties combined.
• 71% of car commuters drive alone to their jobs. The figure was 65% in 1996.⁸
• A likely reason for this loss in market share is that HOV lane construction decreases travel time in other lanes, making solodriving more attractive.
• The drop in market share of HOVs despite spending millions on HOV lanes shows the concept is a boondoggle. No business would spend money on something that results in a drop in market share.

Carpool lanes are promoted by highway construction interests:

• "HOV lanes are a great success" claimed Santa Clara County's highway engineers³ in their press release. In fact, it was not a success either in reduction of VMT or of solodrivers. Their "success" is based solely at looking at HOV counts and deliberately ignoring solodrivers.³ "Failure" would have been more appropriate for their press release title.
• Also not taken into account was that most of the increase in HOVs resulted from a switch from parallel routes to the less congested HOV lane. Paralleling routes would decrease percent of HOVs with this scenario. While no data was taken on parallel routes, the decrease in market share of HOVs indicates this is occurring. The false conclusion of "success" in the press release was based on the assumption that the entire increase in HOVs was the result of switching from solodriving to carpooling.
• Contrary to recent propaganda by Caltrans⁴, carpooling is decreasing overall. Caltrans figures only looked at the highways that have carpool lanes (most had some increases), and omitted ALL mention of how many solodrivers were added to the road as a result of HOV lane construction. For example⁴ "The biggest jump in carpooling occurred on Interstate 680 in Contra Costa County, rising from 495 to 1,567 people [divide by 2 for vehicles] during the peak rush hour since 1994." Not one word about how many solodrivers were added due to the increase in highway capacity.
• HOV lanes are only a success when the goal is to build more highway lanes.
• Why does Caltrans support carpool lanes? To quote Albert Yee, Caltrans chief of highway operations in the Bay Area: "Carpool lanes make it much easier to get environmental clearance" for road projects. "If we want to add a general-purpose lane for all drivers, that's going to get thrown out." ⁵ Caltrans' primary goal is to maximize highway construction.⁶

Increase in Vehicles resulting from adding HOV lanes, San Tomas Expressway (Santa Clara County).³ Vehicle counts in the peak commute direction were taken before and two years after increasing the lanes from 4 to 6. Data from Santa Clara County Transportation Agency. The increase in 2-Occupant does not mean a switch from solodriving as much as a switch from driving parallel roads to the less congested HOV lane, thus decreasing 2-Occupant on paralleling routes. When this figure was made, the definition of HOV nationally was at least three occupants.

Carpool lanes reduce mass transit usage, increase automobiles:

• Note: this section is applicable to the case of constructing HOV lanes parallel to a significant transit corridor, and the only corridor this occurred was I-80 (in the Bay Area).
• A recent RIDES study¹³ states there would be "fewer cars on the road if casual carpooling were not an option." The newly constructed lane on I-80 increased car usage as many carpoolers previously took public transit: 74% of carpooling passengers and 33% of drivers switched from using transit according to the RIDES survey.¹⁷
• The increase in automobiles from the increase in solodrivers is undoubtedly much greater than the increase in automobiles due to switching from public transit to carpooling (about 600 cars per day, says RIDES). Unfortunately, RIDES did not study how many solodrivers were added to the road as a result of lane construction, nor how many of these switched to solodriving from mass transit due to the temporary reduction in travel time on the roadway. Future studies need to query solodrivers to get this data.
  • For more details and analysis, see Casual carpooling reduces mass transit patronage, increases pollution.

Solution for carpool lanes:

• Change HOV lanes into fare lanes or HOT lanes [High Occupancy Toll lanes].
• HOT lanes are more efficient than carpool lanes, as any unused capacity of a carpool lane is used by people paying a fare that varies depending on demand. It is called congestion pricing.
• Use of congestion pricing is not only fair, it is the only way to eliminate traffic congestion.
• Politically, this should end pressure for more highway construction.
• After a testing period, also change existing general lanes, at least half of a freeway, into fare lanes or HOT lanes.
• Above all, stop highway construction including using HOV designation as a ruse!

Three reasons why carpool lanes harm mass transit:

• Carpool lanes greatly increase solodriving, the main competitor to transit in the urban transportation market.
• The minority HOV lane users who actually switch from other modes are mostly former transit patrons (on a corridor with significant transit usage or if a major transit line is built in the future).
• Decreasing automobile travel time probably decreases transit usage, a deduction of simple marketing principles applied to the urban transportation market. [This is the only statement that does not have data backing up the point, because there is no data to my knowledge.]

Carpool lane facts

HOV lanes cause huge solo driver increase on Montague Expressway, Traffic engineers' disinformation on HOVs

HOV lanes cause huge solo driver increase on San Tomas Expressway and Rt. 237

Reallocate HOV lane construction funds

Casual carpooling reduces transit patronage, increases pollution

MTS rebuts RIDES claims

Bay Area Commuters data, 1980 & 1990 Censuses

Also see the Federal Transit Administration web site about HOV lanes:

Re-Thinking HOV - High Occupancy Vehicle Facilities and the Public Interest

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Sources:

1 Source: RIDES study quoted in Mercury News 1/24/99, p. 4B

2 Mercury News 1/24/99, p. 4B

3 HOV lanes cause huge solo driver increase on Montague Expressway; Traffic engineers' disinformation on HOVs:
moderntransit.org/articles/hov-disinfo.html

HOV lanes cause huge solo driver increase on San Tomas Expressway and Rt. 237:
moderntransit.org/articles/hov-santomas-237.html

4 "Carpool Trivia" by Caltrans in Mercury News, 1/24/99, p. 1B.

5 Mercury News, 10/18/97, p. 1A, 22A.

6 Caltrans' unstated goal: moderntransit.org/ctc/ctc07.html#caltrans

7 Non-attainment of Clean Air Act at BAAQMD web site at http://sparc2.baaqmd.gov/sip/aboutsip.htm. Web page is called BAAQMD SIP.

8 RIDES report "How Bay Area Residents Commute," Table 5, on web site: http://www.rides.org/plan/pcmode.html

9 Much detail provided by the Free Market for Transportation Plan by the Modern Transit Society at moderntransit.org/fmt

10 Details in U.S. News&World Report, 2/8/99, p. 28

11 From a Rt. 237 questionnaire [Caltrans report dated March 1, 1989]

12 Employee Parking Cashout and Results of 10 studies

13 Rides report at http://www.rides.org/lv2corner/lv3ccrpt/cc3survey6.html
The report continues by clicking "next" or click "index."

14 Source: MTC Working Paper 5 from their web site, Table23.XLS. This is abridged on our website at
moderntransit.org/hov/ba-census.html. The original is at http://www.mtc.ca.gov/datamart/census.htm#WP (zipped, exel, win file).

15 "Demographics, Trends and Air Quality Working Paper" by SCCTA, dated Dec. 1990, page 37.

16 Letter from BAAQMD to MTC re: MTC's RTP, dated 9/30/98, page 1. From BAAQMD web site. File is mtclet.pdf

17 RIDES data on web page
http://www.rides.org/lv2corner/lv3ccrpt/cc3survey7.html
The report continues by clicking "next" or click "index."

18 Carpool lanes are also called HOV lanes or diamond lanes. The original term is High Occupancy Vehicle [HOV] lanes.