Rush hour

Rush hour is the daily interval when many people want to use the same roads at once, turning an ordinary commute into a problem of scarcity and coordination. In the book’s account, its significance is twofold: pricing can make the costs of peak-time driving visible and encourage people to choose alternatives, but traffic remains a decentralized system whose jams have causes beyond the number of cars alone.

Scarce Road Space and the Price of a Trip

Congestion pricing, an idea dating to the 1920s and most strongly advocated by economist William Vickrey, treats road space as a scarce resource. When a principal route into a city is free, drivers have little reason to consider whether their own trip is worth making at the busiest time. A rush-hour toll changes that calculation: some commuters may leave earlier or later, use public transportation, or work from home. The aim is not simply to charge for driving, but to make the costs and benefits of the choice more apparent to the person making it.

The case for pricing follows from the difference between a private decision and its shared consequence. A driver who joins a crowded road adds to the delays experienced by others, while the monetary cost of that delay is not necessarily reflected in the driver’s own decision. A toll is an attempt to collect that bill and to spread demand across times and modes of travel. If it reduces the number of vehicles below the road’s capacity, it can prevent jams caused by sheer congestion.

London and Resistance to Peak-Time Charges

London put the principle into practice in February 2003, when Mayor Ken Livingstone’s city began charging drivers to enter central London between 7 a.m. and 6:30 p.m. The charge was £5; a driver recorded by one of the city’s 230 cameras without having paid faced an £80 fine. The scheme was expected to raise £180 million a year for public transportation and reduce congestion by 20 percent. Livingstone had to withstand extensive lobbying against the plan, despite traffic pressure being severe enough to turn an avowed socialist into an advocate of a policy welcomed by capitalist economists.

The political difficulty was especially marked in the United States. Many Americans dislike tolls in general and are even more resistant to paying extra to drive at rush hour. Commuters often feel they have no practical choice about when or how to travel, while the prospect of wealthier drivers paying to move along clearer roads can seem unfair. In the account of a failed attempt to introduce congestion pricing on the San Francisco Bay Bridge, researchers concluded that voters and politicians would have to be convinced that no alternatives remained before accepting such a scheme. Some New York City bridges and tunnels do charge more at peak times, but these are exceptions.

That resistance sits alongside familiar forms of time-sensitive pricing elsewhere. Long-distance calls cost more during the day, drinks may be cheaper during happy hour, and travel to Las Vegas costs more on weekends than on weekdays. These prices rise with demand and fall when demand is lower; rush-hour road use is distinctive in how reluctant Americans have been to accept a monetary price at all.

Singapore and the Choice to Drive

Singapore began congestion pricing in 1975, initially charging vehicles entering the central business district during rush hour. The system later extended charges to entry at any time of day. Its enforcement and pricing also changed: manual license-plate recording gave way to electronic smart cards attached to car dashboards, which deduct payment when a vehicle enters a charge zone. The automatic deduction makes evasion difficult and gives drivers an immediate indication of the cost of entering.

Singapore refined the charges to distinguish among periods of demand. Its “peak-within-peak” rates make driving between 7:30 and 8 a.m. half as expensive as driving between 8 and 9 a.m.; the system also includes evening pricing. Weekend-only cars receive tax breaks and price rebates. The book reports that traffic in Singapore is much better than in London or New York, even though Singapore has more cars per mile of road than any Western country, while noting that the country is very small.

The account emphasizes that Singapore’s approach leaves the decision about whether to drive with individuals, despite the country’s authoritarian government. Mexico City’s license-plate restrictions offer a contrast: a plate ending in 5 or 6 cannot be driven on Monday, other final digits are assigned other weekdays, and everyone may drive on weekends. The policy was intended to curb air pollution, not simply congestion, but it did little to reduce traffic. Drivers had no particular incentive to find alternatives on days when they could drive, and some bought second cars for their prohibited days. A price can give a driver a reason to reconsider a trip; a rotating prohibition does not necessarily change the attraction of driving on the remaining days.

The Limits of Pricing and the Traffic Flow

A toll can address only some traffic jams. A highway lane is estimated to accommodate about 1,800 cars an hour when drivers leave two seconds between vehicles; on a fast-moving California freeway, capacity can reach 2,400. If pricing keeps traffic below the relevant capacity, it can help prevent jams caused by too many vehicles on the road. It cannot prevent accidents, construction delays, or disruption associated with on-ramps and off-ramps. Smaller features also matter, including dips, curves, inclines, and a slow truck in the right lane; some scientists argue that jams can occasionally arise for no apparent reason.

Rush-hour traffic therefore brings the book’s larger problem of decentralization into view. Each driver follows simple rules—avoid hitting the car ahead, change lanes when possible, and drive as fast as conditions safely allow—while trying to get ahead and, at the same time, move with the traffic as a whole. Although these individual aims can sometimes be coordinated, on a crowded highway they often produce a snarled flow. The book’s conclusion is not that a correctly chosen toll makes every commute smooth: pricing may make traffic better reflect the value drivers place on their trips, but it does not remove the many other sources of disruption.