David Alpert on driverless cars

I’ve been meaning to write a “how this urbanist stopped worrying and learned to love the driverless car” post for a while, but I’ve finally been spurred into action by this piece in the Atlantic Cities by Greater Greater Washington founder David Alpert.  Right up front I want to say I still have a lot of concerns about how we plan and incorporate robot cars, but on this issue of competing road users, I take a different view.

Alpert’s contention is that in our society’s haste to adopt driverless cars, we will “intensify current tensions” between drivers (more accurately called passengers in a robot car-filled world of the future) and non-auto users, such as pedestrians and cyclists, who are trying to use the same right of way.  I think this case is overstated for a number of reasons.

The author’s main evidence for the idea that tensions will be increased is reference to an animation done by some computer scientists that showed how to optimize an intersection when most of the cars are driverless, thus increasing flow.  According to the article,

[H]uman-driven cars would have to wait for a signal that would be optimized based on what everyone else is doing. And the same would be true of pedestrians and bike riders.

And to that Alpert reacts:

That certainly sounds like all other users of the road will have to act at the convenience of the driverless cars, under constraints designed to maximize vehicle movement instead of balancing the needs of various users…

The video even depicts an intersection with a whopping 12 lanes for each roadway, at a time when most transportation professionals have come to believe that grids of smaller roads, not mega-arterials, are the best approach to mobility in metropolitan areas.

Driverless cars, therefore, are poised to trigger a whole new round of pressure to further redesign intersections for the throughput of vehicles above all else.

I’m not sure how this one animation demonstrates why driverless cars would trigger a gush of road-building or elimination of non-auto facilities.  Setting aside the fact that I’m sure this animation was developed as a proof-of-concept (I can hear the research team now: “If we use 12 lanes in each direction, it will look even more impressive!”), this leads me to my first objection to the premise that driverless cars will increase tensions.

Driverless cars don’t make bad roads, people make bad roads

As Alpert himself states, “Already, cities host ongoing and raucous debates over the role of cars versus people on their streets. For over 50 years, traffic engineers with the same dreams about optimizing whizzing cars have designed and redesigned intersections to move more and more vehicles.”  Yes, and we’ll continue to have this debate into the future whether robot cars are adopted or not.  Given that gradual adoption of this technology is the most likely scenario (more on that later), I don’t see auto users getting more vocal (than they already are) about road capacity because there car has a few more widgets.

Building a balanced transportation system that looks at the full picture of quality of life rather than just mobility and speed will continue to be a challenge, although we seem to be making some progress in that direction.  Issues of public health, environmental impact and land use impacts will probably always take some extra effort to incorporate into transportation decision-making, an effort organizations like Greater Greater Washington should continue to make.  I view this as an institutional problem, failing to bring full information about transportation systems impacts to the design table, and it should be addressed in our decision-making processes.

12-lane at-grade intersections would make any cityscape pretty awful, but that leads me to my second objection:

Driverless cars can do more with less

Maybe the computer scientists at UT Austin should have showed a 2-lane 4-way intersection with driverless cars instead of a 12-lane intersection.  They also should have showed a comparison with a present day intersection.  One of the potential benefits of driverless cars is squeezing more flow or capacity out of the road systems we already have.  Cars can drive closer together, and yes, maybe intersections can look more India-like.  Potentially, we’ll get more from our existing concrete without having to widen or reduce non-auto infrastructure.

There is also this nagging funding issue.  In Minnesota for example, we already can’t pay for all the roads we want.  So 1) a huge explosion of more road-building probably isn’t likely and 2) driverless cars give us kind of another way out: if we’re intent on adding more capacity, maybe we can make our vehicles smarter rather than our roads wider.

And finally:

Driverless cars are safer

The first forays into “driverless cars” are about collision detection and avoidance (see a long list of existing implementation here).  Google’s driverless car has driven 200,000 miles and been involved in two accidents (both while being driven by a human).  Before any cars are driving themselves around, their computer brains will just be allowed to stop us from having accidents.  This is good for auto users and others alike.   And their adoption will happen gradually (they’ll be pretty expensive at first).

It seems obvious that driverless cars will be programmed to not hit pedestrians and cyclists.  Driverless cars will never (or very rarely) drive in a bike lane or right-hook a cyclist.  And for the next fifty years, they’ll probably be operating on roadways that look very similar to what we have today, pedestrian cross-walks and all.  The dys/utopian future where we have streets with tightly-spaced driverless cars traveling 200 mph is quite a ways off, and when that happens, why shouldn’t they be limited access and/or grade separated?  Wouldn’t we require the same of high-speed rail?

Again, there are lots of other potential negative impacts we need to be aware of as driverless cars become common (see my summary here), but I think these can be addressed by human policy decisions.  We also need to take some drastic action on emissions from transportation that contribute to climate change, and robot cars will likely not have a measurable impact there for some time (it’s also possible our action, if we take any, may actually delay their deployment).

Robot cars could offer urbanists a myriad of benefits that Alpert doesn’t address (but which others have covered in detail, but that should probably wait for another post.

Alternative transportation funding mechanisms gaining traction

CC licensed by flickr user Caveman 92223

Mission, Kansas and the State of Rhode Island are both exploring alternative methods for funding road construction, maintenance and transit.  The Rhode Island Senate will be studying how a mileage tax, or VMT tax would work in the state.  A VMT tax isn’t new in concept, Oregon has studied it, and the Dutch are doing it, this would add another US state to the list.  Rhode Island is apparently feeling the effects of falling gas tax revenue, and searching for a better funding mechanism.

In Kansas, the city of Mission is considering a new fee based on the trips assumed to be generated by your specific property.  Single-family properties generate on average fewer trips than a big box store, and thus are taxed less.  This type of trip-generation model is the basis for how engineers currently develop city and regional traffic models.  This is similar to a mileage tax, but using a slightly different (less accurate) method of estimating how much individuals are using the roads.  In Mission, a single-family residence would pay $72 per year of this tax.  The City figures that this new tax would bring in about $800,000 per year.

Using 2008 Census estimates, a similar tax on Twin Cities-area single-family homes only would net the region over $62.8 million per year, or over $100 million if you extended the same tax to all units.  Keep in mind that in Mission they believe the burden will actually fall more heavily on commercial properties than residential, so this amount is probably less than half of what a hypothetical Twin Cities program might net.  For some reference, spending in the state on roads and bridges in 2007 was over $2 billion.

These use-based fees may becoming more common as it becomes more obvious that road users are not paying their way (and haven’t for a while).  In addition, as we switch from gasoline to other fuels, funding sources based on one particular fuel will be less and less useful.

Cities prepare for the electric car, but are they thinking about the roads?

Potholes - courtesy flickr user MSVG

The New York Times describes a number of cities, mostly in California, that are preparing their communities for the adoption of more electric vehicles. Primarily this means installing charging stations in public places and addressing code issues related to charging stations at single family homes. According to the article, San Francisco will soon have a new ordinance that requires new structures have the wiring to accommodate charging stations.

The article doesn’t address the other half of the auto infrastructure: the roads. To “prepare” for the electric car, and probably even an efficient system that doesn’t include the electric car, road funding needs to change. We already know that users now only pay about half of the cost of roads, which means there are no market signals for road users to choose the most efficient mode or “consume” an appropriate amount of transportation service (miles traveled). We also have some serious deferred maintenance issues.  If electric vehicles are adopted in large numbers funding for roads, which comes in large part from the gas tax, will continue to dry up.

So besides building charging stations and beefing up transmission infrastructure, cities, counties and states (and users, if they want good roads) should be advocating for a mileage-based fee, similar to what has been studied in Oregon and implemented in the Netherlands, to pay for road building and maintenance. The gas tax would probably have to stay, but as a way to put a price on carbon pollution rather than fund transportation.

This new mileage fee could be tacked unto your home electricity bill if you had a charging station, but that would probably mean a lot of creative solutions would pop up (solar panels) to avoid the fee. While this would have it’s environmental benefits, it wouldn’t solve the transportation funding problem. So the fee should be based purely on mileage, not the fuel used. Existing technology is adequate to provide a method to assess the fee, including addressing privacy concerns. The Oregon pilot has shown that this can work, it’s only a matter of political will to implement it.

US Road Funding From Non-Users At All Time High

According to a new report by Subsidy Scope from the Pew Charitable Trusts, user fees for the construction and maintenance of US highways were at an all time low in 2007.  In other words, fees from non-users are at an all time high ($70 billion).  In 2007, 51% of funds for construction and maintenance was generated from user fees, down from 71 percent 40 years ago.  User fees include the gas tax, while non-user fees are things like bonds from local governments and sales and property taxes.

The main causes of this change according to Subsidy Scope?  No increase in the federal gas tax since 1993 and an increasing reliance on state and local governments to pay for roads.  People also drive less as fuel prices increase.  No mention of increasing use of alternative fuel vehicles, but surely that will play an increasing role in revenue declines in the future.

In contrast, I think 25% of transit’s costs are paid through user fees, although please correct me if I’m wrong.  Here is some data to wade through if you’re interested.  It should also be noted that both of these percentages include only internalized costs of roads and transit, not externalized (non-monetized) societal costs (pollution, congestion, etc).