By Austin Patten

It might seem unusual to discuss car technology in a blog devoted to urbanism, but as many readers know, the automobile has a huge impact on our built environment. This is why it strikes me as interesting that we’ve gotten to the point where luxury cars are now offering systems like dynamic radar cruise control, which enables the vehicle to automatically maintain a certain distance between it and the car in front without human intervention, and lane departure warning systems, which warn drivers when they unintentionally drift out of their lanes. Of course, these and similar technologies are no substitution for an actual driver at this point, but the fact remains that eventually they will be. As these technologies develop and proliferate, they will become standard in all automobiles, much as automatic windows, airbags, and anti-lock brakes have in the past. Over time, we will eventually transition to a driverless society, at least on the highway. (A bold statement, I know, but I’ll admit that the time frame is clearly up for debate.)

So what does this mean for our cities? A lot, it turns out, as long as we’re talking about our highway system. You see, humans are less than perfect drivers. We get in accidents, we cut other drivers off, we get lost, we rubberneck, we speed up and slow down too much, we break laws, and sometimes we’d rather pay attention to our phones than the road. This all leads to more traffic congestion. Even more important than human error is human reaction time. Traffic engineers will tell you that a highway can handle only a certain number of cars per hour, depending on the number of lanes. This is because you can only fit so many cars on the road at a time while maintaining a moderate speed and a safe distance between cars. The “safe distance” required only grows at higher speeds because of human reaction time. All of this human-caused congestion adds up to quite a lot, but it’s all avoidable.

Computer systems, on the other hand, are a different story. They react much faster, and assuming they’re designed and programmed correctly, they don’t make mistakes, and they could follow the car in front much more closely while still having plenty of time to react. With more perfect, more responsive “drivers”, we can pack our cars more densely on the road without sacrificing speed or safety. A congested freeway could conceivably fit double the amount of cars or more, maintain high speeds, and (most importantly) do it all using the same amount of lane space as before.

All this new-found surplus capacity that we can expect on our highways and interstates (and it is a significant amount) will mean faster travel throughout our cities, which seems good, but can be potentially threatening too. Highways that can handle twice as many cars may never have to be expanded again, but they could also open up vast new areas on the fringes of our cities to development, much in the way that constructing the interstate system along with countless other highways and beltways in the past has made our modern suburbs possible. As we make the countryside more and more accessible, more development inevitably follows.

An alternative to this future, of course, is to make better automobile technology work to our advantage by balancing the extra highway capacity with highway removal projects in our urban centers where the highways are most damaging to our neighborhoods. Proposals like  tearing down the Sheridan Expressway through the Bronx or removing the Gardiner Expressway through Toronto may eventually become a lot more feasible if we are able to easily shift some of the traffic burden onto other freeways that can handle the increased flow. Here’s hoping our future policymakers make the right choice.


Austin Patten is an urban planner who enjoys working in Downtown Denver. He received his Master’s degree in Urban & Regional Planning from the University of Colorado at Denver in 2009 and is interested in transportation, urban design, pizza, and hanging out with friends.