A Better Way to Improve Transit to Dulles

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On July 3rd Loudoun County’s supervisors are to decide whether to spend taxpayers’ money supporting Phase 2 of the $2.8 billion rail extension to Dulles Airport and beyond.

They have three strong reasons to decline their support:

First, the proposed transit service will be slow, and Loudoun residents value their time highly. Rail services that require every train to stop at every station provide slower door-to-door service than express buses. For example, travel by the rail system from Wiehle Avenue to the Pentagon would take 57 minutes, involving 12 stops, the one at Rosslyn requiring a train change. In contrast, express bus service can provide this service in less than thirty minutes.

Second, the method selected to finance the rail expansion — by trebling the 2012 $2.25 toll level on the Dulles Toll Road to $6.75 by 2018 — is calculated to “toll off” some 25 million trips a year, some five million of them by Loudoun residents. These five million trips would average over 13,600 trips a day, which is more than the number of daily trips expected to be generated in the County by the rail system. So the project is likely to reduce mobility in the County.

Third, it is difficult to take seriously the claim that the project would promote economic development. Transportation projects that reduce mobility do not stimulate development. And, according to the Board of Supervisors’ own consultants, increased development stimulated close to rail stations is usually balanced by reduced development elsewhere.

But what about rail projects in other parts of Virginia? Was Governor McDonnell right to decline to finance, for example, the “Light Rail” proposed for Virginia Beach?

Railroad passenger service was developed in the nineteenth century as a travel mode superior to horse-drawn buses. But it was out-dated at the beginning of the twentieth by the invention of the motorized bus, which was not confined to fixed guideways. Bus-based services have major advantages over rail-based ones:

First, buses are available in different sizes, and can offer different comfort standards, to match service demand. They can run on different kinds of road, e.g. local roads or freeways, and do not require travelers to make so many changes at “stations”.

Second, bus services are more flexible. For example, they can be changed much more easily than rail service in response to changes in travel demand.

Third, when every train has to stop at every station, travel time is increased. Virginia is a high-income state, and its people dislike long journey times.

Fourth, bus services can be provided competitively, which exerts downward pressure on costs and encourages services that meet passenger demand. Rail transit, on the other hand, is generally provided by government monopoly.

Fifth, rubber-tired systems have more seated-passenger capacity than railroads. According to the Highway Capacity Manual, the theoretical capacity of a dedicated bus lane exceeds 1,200 buses an hour. If 45-seat buses are used, a dedicated lane can accommodate 54,000 seated passengers per hour in one direction, more than sufficient to meet Virginia’s needs.

Finally, express lanes can meet the demand for transit and have significant excess capacity for other purposes. Where lane capacity is 1,000 buses per hour, 200 45-seat buses can carry 9,000 seated passengers per hour and still leave over 80 percent of road capacity available for other vehicles, which can be electronically tolled.

This excess capacity for tolled vehicles available on bus–carrying expressway lanes points to a better way for Virginia to meet its population’s transit demands. Such tolled lanes are now actually being constructed in Virginia to expand segments of the Washington Beltway. Express lanes with variable tolls, electronically collected, were pioneered in the 1990s by the California Private Transportation Company which conceived, financed, designed and provided them in the median of a ten-mile stretch of California’s State Route 91, some 30 miles east of Los Angeles. These tolled lanes are made available at no charge to buses and specific types of high-occupancy vehicles (such as van-pools). Other vehicles can use the lanes if tolls are paid. Payments are collected electronically from customers’ pre-paid accounts, the payment levels being set to ensure congestion-free travel at all times. Tolls for that 10-mile stretch now range from $1.30 for much of the night to $8.95 at 4:00 PM on Thursday afternoons. All income classes use the tolled lanes, with more women than men switching to them. Those who choose not to pay stay on the non-toll lanes.

These electronically tolled lanes, which can be privately provided, have many advantages:

  • They offer buses speedy congestion-free travel;
  • Single-occupant vehicles get premium service and save time;
  • Those not using the express lanes benefit from reduced congestion in other lanes; and
  • The fees collected can cover all or part of the express lane costs.

Such lanes, if provided on the Dulles Airport Access Road, would be a superior and less costly alternative to Phase 2 of the Silver Line, and could also be offered in other parts of Virginia.

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About Gabriel Roth

Gabriel Roth served for twenty years as a transport economist in the World Bank, which published his 1987 book: The Private Provision of Public Services in Developing Countries.
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7 Responses to A Better Way to Improve Transit to Dulles

  1. Olivia Jenney says:


    In my opinion,the highest priority to provide successful ridership requires parking to access buses. Today (and since 1980 and well before) Fairfax County’s prideful policy determined no available parking to a large percentage of ridership – preferring “Kiss & Ride” or other bus route access. This hateful parking policy eliminates those who cannot park their cars, neither live on a bus route, nor have car pool access to the bus stops.I believe this policy will continue for rides to rail stations. Outrageous!

    Many investors have positioned themselves through land acquisition along the proposed rail route. Buses should only enhance riders accessibility to these commercial investments.

    Buses of varying size have enormous appeal – ultimately saving fuel and maintenance costs. Smaller buses on many 2-4 lane roads reduce hazarda, increase ridership and reduce time spent point to point.

  2. Gabriel Roth says:

    I agree with much of Olivia’s comment, but do not see whether she is for or against Phase 2 of Metrorail. As buses can change their routes more easily than rail to be accessible to parking facilities, her point seems more applicable to rail.

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  4. Bill Harshaw says:

    One advantage of rail is reliability. Express bus depends for speed on law and enforcement to keep other commuters out of express bus lanes. The experience of HOV on Rte 66 shows we can’t depend on law and enforcement. The 57 minutes/30 minute comparison assumes the buses have clear sailing. They won’t on many days.

    Using Pentagon as the destination skews the comparison–how about Farragut West?

    • Gabriel Roth says:

      If we are to compare bus and rail modes, we need to do so validly. Rail trains enjoy dedicated rights-of-way, but Bill assumes that buses operate in mixed traffic. Such a comparison is not valid, as buses with dedicated rights-of-way can provide a high degree of reliability.

      Agreed that there are problems running buses under ground, and that it is hard for them to get quickly to Farragut West in mixed traffic. But travel in the Dulles Airport area is above ground for both rail and bus. So the Pentagon destination provides a valid comparison while the Farragut West comparison is the one skewed.

  5. EW says:

    Another consideration is that trains are more comfortable than busses. Many people get car-sick or feel nauseaus on a bus, but do not on trains. One can get up and walk around on a train – something you can’t readily do on a bus. Most people find it more convenient to read on a bus than on a train. A lot of people I know seek out trains (or subway, light rail) over busses because they simply are more comfortable.

    • Gabriel Roth says:

      These considerations are valid, but are they not more relevant to long-distance rail than to transit? And the comforts mentioned by EW are certainly not important enough to persuade other Virginia travelers to pay what they cost to provide.

      And remember that buses, also, can offer high comfort standards, including for example Wi-Fi and power sources for those wishing to use their computers.

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