Mull this one over next you're stuck in traffic on your way into or out of work.
What if instead of leaving your house and chancing the congestion on your rush-hour commute, you could reserve a space on the road just like you reserve a table at a restaurant? Then you'd simply drive to the highway or major intersection at the appropriate time, announce via technology that you're here, pay a market fee (just as you pay your check after eating), then enjoy a smooth ride. Sure, you'd lose one more excuse for being late to the office — but a considerably miserable part of your day would feel considerably less miserable.
The concept may seem too theoretical to entertain. But as transport scholar David Levinson points out at his Transportationist blog, it's not so wild that we needn't bother discussing it. In fact, the systems researchers Matteo Vasirani and Sascha Ossowski of University Rey Juan Carlos in Madrid have made road reservations the subject of a lot of recent study.
When you break it down into little pieces, the idea stops feeling so far-fetched. The technology already exists: intelligent infrastructure that can communicate via digital networks, in-car navigation systems, payment transponders like EZ-Pass. As our Emily Badger has explained, systems researchers are already planning the day when "intersection managers" direct traffic with ultimate efficiency. Vasirani and Ossowski have simply added the element of road pricing into the mix.
The researchers set their hypothetical sights on a reservation system in metropolitan Madrid. The big dots circled in red on this map of the city are where commuters could reserve space on the urban road network:
Figure via Vasirani, M., & Ossowski, S. (2012). A market-inspired approach for intersection management in urban road traffic networks. Journal of Artificial Intelligence Research, 43(1), 621-659 [PDF].
So let's say you want to drive through one of these points. As you approach, your car contacts the "intersection manager" and tries to make a reservation. The intersection manager crunches the data on all other cars on the road, decides whether it can fit you in, and tells you how much a place will cost. At this point, to reserve a space, you pay a small reservation fee. That's to keep people from reserving spaces on roads all over town.
Once your road reservation is made, then you continue on course to arrive at the intersection within a certain time window — as with restaurants, there can be a bit of flexibility here, though not too much. As you cross into the intersection on the desired course, you pay the remainder of the reservation cost. Naturally, fees will be highest along the most desirable corridors, for the same reason it's hard to get a table at Komi.
Now let's say you can't get your first-choice reservation. You still have options to get into town. For starters, you can choose another route and make a reservation with that intersection manager. You can also simply show up at the intersection and hope the manager finds you a place; again, as at a restaurant, something might open up, but you could be waiting a while. You can also brush past the manager and continue on the road anyway, but you'd risk causing an accident or getting a ticket.
When the system is operating at its theoretical peak, the prices at various intersections create incentives for people to find alternate commute routes — or, of course, to take public transit. Those incentives, in turn, should decrease congestion. (On the flip side, if managers ask too much for space on the road, their route will go out of business.) Sure enough, when Vasirani and Ossowski ran their idea through a model of Madrid traffic, they found that as intersections profits increased, general travel times across the city decreased.
Of course, the entire system of road reservations can be adjusted for a city's particular social taste. Certain routes can be kept free to everyone, with the understanding that these public lanes will be more congested, just as major highways are today. Local governments who want to increase transportation revenue could tilt the reservation formula toward profit, while those preferring a welfare model could tip it the other direction. Agencies could even get creative with monthly commuter passes based on zip codes, or reduced rates for reservations made far in advance.
Obviously such a system would take some getting used to. Commuters are struggling with HOT lanes in many cities, and a road reservation network is like a HOT lane on steroids. The system would probably work best in a world of driverless cars, first to limit distracted driving, and second to cut down on violations. Some people might object on privacy grounds, but really a reservation system wouldn't track you much more precisely than highway tolls already do. And no doubt some unforeseen problems would pop up concerned certain classes of vehicles — taxis, for instance, or commercial trucks.
So yes, it's a bit of a daydream. Still there are at least two times every day when urban commuters would probably be willing to give this daydream a shot at coming true.