Bacon's Rebellion

Democracy Thrives in Sunlight

Digging Yourself a Deep Hole? Dig Faster!

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by

James A. Bacon
in

Barton Hinkle with the Richmond Times-Dispatch is one of the few newspaper pundits in Virginia to take the trouble to probe beneath the he-said-she-said coverage of the taxes-and-transportation debate. He actually — gasp! — does his own research. And sometimes he offers insights that are new even to an old journalistic hand who, like myself, has been covering land use and transportation issues for years.

Witness Hinkle’s column today. He makes a number of valid points but one stands out: Over the past two decades, he observes, the number of lane-miles of road and highway overseen by the Virginia Department of Transportation has increased nine percent. By contrast, the number of lane-miles increased only 2.4 percent nationally over the same period.

That creates a problem. As Hinkle notes, “VDOT faces a mathematical dilemma imposed by the nature of its business: Current budget growth accelerates future budget growth. That’s because VDOT has to spend money on maintenance as well as construction. A dollar spent on construction this year creates demand maintenance dollars in future roads.”

Thus, the relentless climb in maintenance funding is due to more than the faster-than-inflation increase in construction costs — it’s due to the steady expansion of Virginia’s road and highway network.

There’s one aspect to VDOT’s dilemma that bears illuminating. Much of that nine percent increase in lane-miles is, for all intents, useless to the vast majority of citizens. Those lane-miles reside primarily in cul de sac subdivisions, which means they are utilized by only a handful of subdvision residents and the occasional visiting UPS truck. (To see what I mean, study the photo above from Overland Park, Kansas.) I don’t know the figure for increase in lane-miles for critical connector and arterial roads, but I’m certain it’s far lower than nine percent — it’s probably closer to the national average of 2.4 percent.

This gets us to a foundational problem for Virginia’s transportation system: a cul de sac/collector/arterial pattern of road development in which half (or more) of the lane-miles are way underutilized and the other half is overloaded and congested. You don’t see the same mismatch in urban centers where the grid-street system predominates. Urban centers do have quiet side streets with little traffic, but a higher percentage of urban lane-miles is devoted to moving people at faster speeds.

Moral of the story: It’s not how many lane-miles you build, it’s where you build them and how you connect them.

(Photo credit: George Butler Associates, Inc.)

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10 responses to “Digging Yourself a Deep Hole? Dig Faster!”

  1. Jim Patrick Avatar
    Jim Patrick

    Isn’t the solution obvious?
    Privatize the private roads.

  2. Ray Hyde Avatar
    Ray Hyde

    Asserting that development patterns and densities affect how far, how often, and by what means people travel, urban designers argue that shape of the local street pattern play a key role in travel. “Connected” residential blocks, the argument goes, associated with less driving by comparison with the circuitous routes of the modern suburban cul-de-sac developments.

    There is little empirical and theoretical support for these claims. A number of studies find either little role for land use in explaining travel behavior, and no evidence that the street network pattern affects either short or long nonwork travel decisions, or else they find that there are too many other competing factors to decide unequivocally. Most assert that more research is necessary.

    Humans are territorial animals and instinctively try to maximize territory and the reason is that territory equates with opportunities and resources.
    However, there are constraints to range — essentially, time and money. In studies for the World Bank and the US Department of Transportation in the 1970s and early 1980s. Zahavi and others find that since ever, and in contemporary societies spanning the full range of economic development, people average about 1 hour per day traveling. This is the travel time budget. Schafer and Victor, who surveyed many travel time studies in the decade subsequent to Zahavi, find the budget continues to hover around one hour. And numerous studies have shown that this travel budget time is no different for gridded street, cul-de-sac, or rural areas. In fact it is relatively constant across the world, including those cities with the best public transit systems.

    However, it is true that there are differences in the amount of travel various road systems can support. Two two lane roads operating at 35 mph can support more traffic and more destinations than a four lane road operating at 55 mph. It is not at all clear that the benefits extend all the way down to traditional street grid neighborhoods for several reasons. One is that such neighborhoods exhibit more and shorter trips within the allowed travel budget, one is that those trips occur at lowe speeds and higher traffic densities, leading to more pollution, and one is the higher incidence of left turns, which substantially reduces the flow such streets can carry.

    Jim patrick makes an excellent comment, and many subdivision roads are already not state maintained.

  3. Jerry Fuhrman Avatar
    Jerry Fuhrman

    I’ve come to respect Bart Hinkle too. He is level-headed an does his homework. The world could use a few more like him.

  4. James Young Avatar
    James Young

    Interesting analysis by Hinkle (and you, Jim), but neither of you take the next step: I have to assume that the maintenance costs of these vastly underutilized roads are far below those of major thoroughfares, because of lesser wear and tear.

    As a for instance, I live in one such community, between two cross-streets in a road that ends in a cul-de-sac. The only “repair” that we’ve seen in the twelve years that I’ve lived there was due to damage done to curbs by an irresponsible contractor hauling away the remains of a blizzard. Certainly, no paving has been necessary. This is as contrasted to the main thoroughfare through the community, which is in the process of being repaved for a second time since we moved in (and probably wouldn’t need it, had Montclair had the wit to remain a gated community).

  5. Jim Bacon Avatar
    Jim Bacon

    Valid point, Jim. Some of the wear and tear comes from traffic, which afflicts some roads significantly more than others, as you observe, and some comes from pounding by the elements. How it all washes out, I’m not sure, but my anecdotal observation is consistent with yours on that point.

  6. Jim Bacon Avatar
    Jim Bacon

    Jim, Here’s another question to ask: What would the overall maintenance costs be if the traffic was spread more evenly over the roads instead of concentrated on a handful of collectors and arterials? Does the damage accumulate arithmetically or geometrically under the pounding of heavy traffic? I have no idea what the answer is… just trying to think through the issue you raised.

  7. Ray Hyde Avatar
    Ray Hyde

    Now, I like that last one. That has some interesting cost ramifications.

    Young might have a point, my driveway was paved 15 years ago. It needs repair now, but it was no way built to state standards.

    Developers arn’t stupid. Don’t you suppose that they design these things for maximum land use and minimum development?

    Take a look at the picture. In the bottom left is a cul-de-sac, and another in the top right. I count six intersections and one crossing of a main road to get from one to another, and three left turns. Now superimpose a grid on the picture and figure out what it would take.

  8. Jim Patrick Avatar
    Jim Patrick

    Come on folks, look at the road pattern. They are —for all intents and purposes— private roads. Privatize them.

    Young makes the true, but diversionary, mistake about low traffic equating to low maintainence. It ignores the fact that private-use (residence only) lane miles account for a lot of paved miles. The lowered per-mile repairs are more than offset by the sheer quantity.

    Statistically, all the new lane miles constructed in Virginia are for private residential use. Construction may not be from VDOT’s budget, but we’re accumulating an enormous maintainence bill.

    Look at the road pattern. Except for the odd tutoring or piano lesson —extremely low volume allowed residential uses— those roads can’t support any other use except residences. The design can’t tolerate higher traffic; they were designed exclusively as residential access and can’t be adapted for commercial or business.

    Bacon rightly keeps harping on ‘user pays based on use’ principles. The photo above is an example of glorified, collective driveways; there is no public use for them, not even potential use. With no use, the public should never be made (taxed) to pay for them. Privatize them.

  9. Jim Patrick Avatar
    Jim Patrick

    PS to the preceding post. By slight redesign, connecting a couple of the roads in the lower left, it would be easy to add practical light commercial or business in a couple of sections.

    Small restaurants, convenience stores, or gas stations could be supported by the development; additional off-highway customers allow some growth potential. Low volume office, eldercare, fitness and professional uses are other possible uses.

    All this reduces residents’ travel somewhat, a savings to them and to state taxpayers. As important, it creates a neighborhood —a community where residents can naturally mingle. Children could safely walk or cyle to somewhere other than a friends house. Old folks can live in their homes longer.

  10. Ray Hyde Avatar
    Ray Hyde

    That is a conundrum, isn’t it? As long as you have the residential use only, then you can make the argument that they ought to be privatized.

    But as soon as you make them grid streets and add commerce, then they are public, and you’d have to take over maintenance. The grid system has more wasted space in multiple intersections and so therefore each square mile of grid supports fewer residences and businesses.

    Intersections are more expensive than roadway, so the tradeoff you make between grids and culs is initial cost vs miles traveled (maybe). If the miles traveled on a grid are not substantially lower, then the lower speed and more frequent stops results in a longer trip and more pollution.

    ????? What is the best deal?

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