7 Ways to Reduce Transportation Waste

The End of Traffic and the Future of Access: A Roadmap to the New Transport Landscape. By David M. Levinson and Kevin J. Krizek.
The End of Traffic and the Future of Access: A Roadmap to the New Transport Landscape. By David M. Levinson and Kevin J. Krizek.

Some 20 years ago a book came out “Stuck in Traffic” by the brilliant Anthony Downs. One of his key points was the “Iron Law of Congestion”, sometimes called “Triple Convergence”, and now called “Induced Demand” which basically said if you expand a road, the extra capacity gets used up by people switching routes, modes, and time of travel. We might also add other effects of road expansion include changing destinations for non-work trips (making longer trips), making trips that would otherwise be foregone, and even changing jobs and houses, as well new development. While Downs did not discover this idea, (e.g. Lewis Mumford had said something similar) he popularized it.

Since Downs wrote the book in 1992, remarkably little has changed in how we travel. Not nothing of course, (travel rose for a few more years and has leveled off overall, and dropped in more recent years on a per-capita basis) but a lot less than you would expect given the changes in information technologies over the same period. No-one is satisfied with this status quo. Everyone is crying out for something different. We believe we can do better than daily congestion, excess pollution, devastating crashes, and all the other ailments associated with our existing transportation systems. In recent posts I identified peak travel, and made a speculative scenario of how traffic might disappear “on its own”. But of course, that won’t happen everywhere, and there are lots of things we can do to manage better.

Roads are perhaps the slowest changing technology. Once laid, they are difficult to move. Parts of the Appian Way, from two millennia ago, are still in use. Famously London could not change its street grid after the 1666 London Fire destroyed most of its buildings, despite an able plan from Sir Christopher Wren.

We can think of transportation as a layered system. There is the earth, on top of which are rights-of-way, within the rights of way are pavements (themselves layered). On the pavements are markings denoting lanes and directions. Above these are traffic control devices like signs and signals. Only then do we get to services, people driving their vehicles, trucks carrying freight, passenger buses, taxis, bicycles, pedestrians, etc. all riding on the layer of roads.

To the dismay of many transportation planners and engineers (many of whom got into the field to build things), the physical layer of the surface transportation network in the United States is largely complete. The projects that are left are projects that were too expensive to build the first (or second, or third) time, (much like the Second Avenue Subway in New York). These Zombie projects do not die, while construction is essentially irreversible, non-construction is easily reversed. In the end though, these are tinkering at the edges. Given the small amount of new construction, most travel 20, 30, or 50 years from now will be on roads that already exist.

Until we go airborne for short trips, we are highly constrained. As the world gets more developed, building new roads is progressively more expensive. The world adapts to the infrastructure that is provided, and builds as close to the right-of-way as possible, making expansion that much more difficult.

While we have scarce right-of-way (scarce in that it is limited, and finite, and at times fully utilized given the applied technologies for its use). We lack time. We have limited energy. This waste has both supply and demand aspects. Yet collectively we don’t do relatively easy things that would reduce the waste of these scarce resources.

  1. Most roads are under-utilized most of the time. We have plenty of capacity outside the peak.
  2. Most of the pavement is unused even at peak times, there are large gaps between vehicles both in terms of the headway between vehicles [1] and the lateral spacing between vehicles (we drive 6′ wide cars in 12′ lanes, often on highways with wide shoulders).
  3. Most seats in most cars are unoccupied most of the time.
  4. Most cars are carrying around far more weight than required to safely move the passenger. While bigger cars tend to be safer for the occupants, they are less safe for non-occupants. This is an inefficient arms race.
  5. Most roads are so wide we use them for storage of vehicles most of the day.
  6. There is a tremendous amount of excess delay at traffic lights, especially at off-peak periods, wasting time (and space).
  7. Most trips during peak periods are not work trips and have temporal flexibility, yet these trips travel in the peak because they are underpriced.
  8. Most trips produce negative externalities (pollution, congestion, noise, risk of crash) in excess of the price paid by their driver. They produce so many of these externalities because they don’t pay for their full cost.

So instead of expansion, we should instead think about ways to use that scarce right-of-way (and our scarce time and energy) more efficiently.

  1. Where there is congestion, we should price roads to encourage use in the off-peak and discourage use in the peak. This revenue should be used for the operations and maintenance of roads and should largely replace existing funding sources (fuel taxes, vehicle taxes, property taxes). Prices need to be systematic, not just on specific routes, to maximize system efficiency. We should avoid having a random set of underutilized toll roads, while free roads remain congested.
  2. Pollution and noise and crash risk should have their own externality charges.
  3. We should encourage narrower vehicles and, for instance, provide two six-foot lanes for narrow vehicles in place of one twelve-foot lane where we can, and promote use of driverless cars so that cars can use less space. Lane widths are standard, and changing them would require changing standards. Ultimately we should move to a model where we don’t need pre-defined lanes, but rather have vehicles move as near each other as possible without colliding, such as we do when walking in crowds.
  4. Cars should be lighter. If all cars were lighter, everyone would be safer. The greatest risk is when big car/truck meets small car. In particular we should encourage use of neighborhood cars that are specialized for local, lower speed travel. This may or may not require private vehicle ownerships as opposed to vehicle rental/sharing.
  5. We should promote technology to enable real-time, ad-hoc ride-sharing (with compensation for the ride provider) to better utilize excess capacity within vehicles. (In many places the compensation is illegal, as it looks and smells like a taxi, which are highly regulated).
  6. We should narrow up roads where we can, and use strategies so that people can share more cars, so we need fewer of them, so we don’t need to spend as much road space for vehicle storage. Road widths are again set by standards, often determined by the fire department (which does not want to back up their trucks).
  7. We should be able to eliminate many traffic signals with appropriate use of roundabouts (and later with driverless vehicles). Given the vacant space available on roads, if vehicles and inter-vehicle communications were better, we should be able to arrange real-time coordination of vehicle movements and have as a goal eliminating almost all stopped delay at undersaturated intersections that are today signalized. Pedestrian/vehicle conflicts might still remain, and require controls.

This is hardly a complete catalog of what we can and should do, but I hope the key point, there is plenty of pavement already, we just need to use it more wisely, comes through.


[1] If we follow the “2 second rule” (2 seconds between two successive vehicle’s front bumpers) (or 1800 vehicles per hour), at 60 mph we have a vehicle density of 30 vehicles per mile, or 176 ft per vehicle. Obviously with congestion, we are wasting time because we don’t increase throughput and we decrease speed, though we increase density. Vehicles are typically 26 ft, so we are using about 7 vehicle lengths for every vehicle we are moving at free flow speed near maximum stable throughput on a pipeline section without a bottleneck.

Paving Streets for the Poor

Marco Gonzalez-Navarro Climent Quintana-Domeque: Paving Streets for the Poor: Experimental Analysis of Infrastructure Effects:

“This study is the first providing experimental evidence on the role of infrastructure in reducing poverty for the urban poor. We do so by means of a first-time street asphalting randomized experiment. Within two years of the intervention, households whose streets were finally paved, and were present both before and after its implementation, increased their consumption of durable goods and acquired more motor vehicles. These impacts were driven in part by street pavement boosting housing wealth, which fueled a rise in collateralized credit use, but also by an increase in the marginal utility of vehicles. A cost-benefit analysis indicates that the economic returns to street pavement in this developing urban context are at least as large as the construction costs.”

Heat buckles pavement, snarling Twin Cities traffic | Minnesota Public Radio News

A couple of days ago from MPR (back when it was summer, not winter), but more fodder for the asphalt vs. concrete war: Heat buckles pavement, snarling Twin Cities traffic

“Heat buckles pavement, snarling Twin Cities traffic
by Nancy Lebens, Minnesota Public Radio
June 6, 2011
St. Paul, Minn. — The Minnesota Department of Transportation is warning motorists to watch out for roads that might buckle without warning.
MnDOT spokesman Kent Barnard said the heat and humidity had caused pavement to heave on some Twin Cities metro highways.
Monday afternoon lanes were closed in I-94 in Minneapolis and St. Paul. Barnard said heat damaged roads in more than 20 places.
Barnard said he has not heard of accidents associated with buckling pavement. But he’d heard reports of damage to cars.
Older concrete highways are more prone to heave up, as debris fills the cracks between the panels, leaving no place for the pavement to expand.
‘The natural expansion places are filled up and so there is no place for that pavement to expand,’ Barnard said. ‘And the stress of that expansion looks for the weakest area. It could be another crack in the pavement or it could happen real close to where the expansion joint actually is.’
There’s no way to predict exactly where pavement will heave. Barnard said motorists should watch the road and not tailgate.
While the roads are still prone to buckle yet through the evening, Barnard said they should be better by the Tuesday morning commute.”

Driven to disrepair? England’s roads under pressure from traffic, weather, spiralling costs and budget cuts

A new report from the UK, echoing the issues in the US … Driven to disrepair? England’s roads under pressure from traffic, weather, spiralling costs and budget cuts – Audit Commission:


England’s 236,000 miles of local roads – used by 30 million drivers every day – are under attack from increasing traffic, severe winters, higher repair costs, and dwindling highways funding.

The challenges faced by the country’s 152 council highways authorities are the subject of a new Audit Commission reportGoing the Distance: Achieving better value for money in road maintenance.

The report highlights how councils can get more for their money, including cost-saving collaborations with neighbours, asset management to show when road maintenance will be most effective, new ways of keeping residents informed, and weighing short-term repairs against long-term resilience.

Between them, council highways authorities are responsible for 98 per cent of the country’s roads*, spending a total of £2.3 billion in 2009/10. Yet, in response to increasing financial pressure on councils, highways budgets are facing significant cuts.

The Commission has found that the cost of maintaining roads is now 50 per cent higher than it was ten years ago, in part due to inflation in road materials and construction costs. Other pressures facing councils are:

  • Road traffic is expected to increase by more than 30 per cent by 2025;
  • In the next three years there will be a 26 per cent drop in government revenue funding and 16 per less capital funding via local transport plans;
  • Damage by utilities works costs nearly £50 million every year.**

Councils must also strike a difficult balance. Public perceptions of whether roads are in good shape are often only skin deep, so potholes and patchworks attract the most criticism. But dealing with these so-called ‘worst first’ surface issues must be weighed against prolonging a road’s ‘whole life’ before it is too late.

Chairman of the Audit Commission, Michael O’Higgins says:

‘Prevention is better than cure, but councils have to consider the safety and insurance risks of damaged surfaces. Roads costs are rising while councils’ belts are tightening. Improvement in A roads seems to have stalled, and the road network overall is starting to deteriorate.’

In cash terms, its road network is a council’s single most valuable asset. Yet councils struggle to apply asset management principles to roads. They cannot be sold, they don’t generate income, indeed they consume large resources. Hardly surprising that some councils see roads as liabilities rather than assets.

But the report urges councils to consider asset management plans, such as Cornwall’s Transport Asset Management Plan (TAMP), which for an investment of £80,000 is driving consistent levels of service and road condition across the whole county. Such plans also indicate when best to intervene with works to extend the whole life of a road, typically a maximum of only 20 years.

The study team found that collaboration pays real dividends. The Midlands Highway Alliance estimates it has delivered £5.1 million savings for councils and £7.8 million for the Highways Agency in its first three years, and it is looking to a further £14 million of savings between 2010 and 2014. Ten authorities in the East of England have also formed an alliance to save £6m over five years, with £3.3 million from shared back office costs alone.

Michael O’Higgins says:

‘Sadly we found collaboration between councils to be rare, with too few councils procuring in cost-saving partnerships.’

‘Pick up any local newspaper and you will see that people care very much about their local roads. In the last national Place Survey, roads were a higher priority with residents than crime or affordable housing. Our report aims to help councillors maintain their local network against a backdrop of reduced funding. Roads in disrepair can put the brakes on trade, economic prosperity, even emergency services. But a well-maintained network helps people, goods and services to move freely and safely.’



I am not convinced about the rising traffic, but the revenue issue and continued aging of infrastructure are quite real.


The Concrete Lobby?

It appears the Concrete Lobby is also taking a sophisticated approach with: whataretherealcosts.org, a campaign in favor of Life-Cycle Cost Analysis (who could be opposed?) backed with research from MIT. I am getting press releases from Laura Braden, who works at Mercury, “a high-stakes public strategy firm”, about their recent CNBC ad, Fox News ad, etc. She has also sent me emails in the past about Building America’s Future (led by Ed Rendell, Arnold Schwarzenegger, and Michael Bloomberg), but this seems a different campaign.

The domain is registered in Portugal by someone with an Admin named “Domain Discreet”. Who is behind this?

Much as I wish it were true, transportation economists don’t finance marketing campaigns in favor of Life-Cycle Cost Analysis.
As an aside about different marketing approaches, compare with local efforts, where the lobby at least says who they are.

Blacktop and whitetop


Why are sidewalks and driveways made of concrete, but publicly owned streets are much more typically made of asphalt? What does this say about private and public goods and priorities? Are we building the public environment on the cheap, yet are willing to invest in concrete for private goods?
Prof Richard de Neufville at MIT uses this as example of the effect of Discount Rate on decisions. He argues if interest rates are higher, the future matters less, so first cost is more important, while if rates are lower, costs in the out-years matter more. He also points out that capital subsidies (as in the Interstate program) warp local decisions to choose investments with higher first costs (i.e. concrete) compared with asphalt.
Back to the first paragraph, I suspect local governments are more concerned with first costs than downstream, i.e. they have a high discount rate, while private homeowners internalize those costs when deciding on driveways.
This doesn’t explain sidewalks though, which are typically provided by developers (as are local streets).

State Roads to Economic Recovery: Policies, Pavements, and Partnerships – Brookings Institution

Brookings Institution will be hosting an event on State Roads to Economic Recovery: Policies, Pavements, and Partnerships – Brookings Institution.
Event Information
When Friday, February 25, 2011 9:00 AM to 1:00 PM
Where Falk Auditorium
The Brookings Institution
1775 Massachusetts Ave., NW
Washington, DC

As the U.S. economy begins a slow climb to recovery, state and local governments are still reeling from the impact of the Great Recession. Revenues have plunged while the demand for key state and local services has soared. Meanwhile, unemployment remains stubbornly high.
On Friday, February 25, The Hamilton Project and the Metropolitan Policy Program at Brookings will host a forum on state strategies that can help close budget deficits while also growing state economies and creating much-needed jobs. Brookings Vice President Bruce Katz will moderate a panel of policy experts and state leaders, including former Pennsylvania Governor Ed Rendell, now a senior fellow at Brookings, and Michael Finney, CEO of the Michigan Economic Development Corporation. The panel will discuss a range of fiscally responsible policy ideas to build the foundation for the next economy.
A second panel of economic experts, moderated by Hamilton Project Director Michael Greenstone, will discuss three new policy proposals to help state and local governments invest more efficiently in infrastructure to promote their long-term economic competitiveness. These papers provide a new approach to arranging public private partnerships to create greater public value and reduce risks; a reorganization of our national highway infrastructure priorities; and the establishment of a not-for-profit, independent advisory firm that would help reduce borrowing costs for municipalities and increase returns for investors. Former Under Secretary for the U.S. Department of Transportation Tyler Duvall will serve as a discussant for the proposals.

I will not be at the event in person, though I will be there in spirit and online, while Matt Kahn presents our joint paper, which is almost ready to be released.
(This is probably the most important work ever to be written on highway finance by two authors who walk to work).