The Genius of the One-Lane Street

It Calms Traffic

2000 block of Spruce.

I'd like to take the adrenaline out of driving. Also the cortisol. Call me a dreamer. Imagine a low-stress commute. 

And I have a dandy tool ready to hand in Philadelphia - the one-lane street. As I've often said, "Put 'em in a cattle chute, and then they'll behave." And that's what a street with only one lane for moving motor vehicles does. I don't know anything else that works as well.

Pine and Spruce streets in Center City Philadelphia became one-lane streets when bike lanes were installed in one of the two lanes that had been devoted to moving motor vehicles. And yes, this change made these streets safer, less stressful, and more pleasant for everybody, and not just bicyclists.

To understand what Pine and Spruce streets were like before they sprouted bike lanes, all we need to do is walk over to neighboring Lombard street and have a look.

Lombard, the Last Two-Lane Street

Lombard runs westbound and is an access route for the South Street bridge and the Schuylkill Expressway; in operation it is basically a race track. Drivers are clearly shifting into interstate mode, performing the abrupt lane changes so dear to Nascar drivers, and occasionally, in their enthusiasm, jumping the curb. My block on Lombard street has lost, I believe, five trees in the last few years. Quite a few children live on the block, but no casualties to report so far.

Pine at 20th.

I think it's worth pointing out that this street was designed to produce precisely the effects that we see. The engineers were focusing on something called Level of Service (LOS) - basically, how many cars can you cram down this street in a given amount of time, and that meant speed. Speed above all, above human life. 

The term Level of Service did not show up until 1965. But it simply gave a name to what the engineers had been doing for a long time. Starting in the late 1960s, with the arrival of things like the U.S. Department of Transportation, the approach actually softened, but the focus remained on Level of Service. 

People had been concerned about the safety of motor vehicle traffic from the very first days of the car, but they weren't in the driver's seat. (See Peter D. Norton, Fighting Traffic: The Dawn of the Motor Age in the American City, 2008.) It wasn't until the arrival of the Vision Zero movement in recent years that a curious idea gained traction: Perhaps speed is not as important as safety. Shocking.

So at least the thinking has started to change. On the street in front of my house on Lombard street, not so much. Frankly, aside from the addition of a bunch of steel bollards to protect the sidewalk (this has been done by various residents and certainly not by the City) very little has changed in the configuration of the street here since I moved onto the block in 1984.

Meanwhile, on South Street

Meanwhile, South street, Lombard's eastbound partner, is a one-lane street for almost all its length, usually with cars parked at both curbs and one traffic lane down the middle. However, down by the South street bridge, one of the curbside lanes, which elsewhere would be a parking lane, is in fact a bike lane. 

So Pine and Spruce both have one parking lane and one bike lane and one motor-vehicle lane. And South has one motor-vehicle lane in the center of the street, and the curbside lanes are devoted to other uses. 

So why does Lombard have two motor-vehicle lanes for most of its length? Of the four blocks - Spruce, Pine, Lombard, and South - it is the only one that retains two motor-vehicle lanes.

Lombard at 22nd.

My question is further complicated by the fact that near the South street bridge, where you would expect the heaviest traffic on Lombard because the bridge is a magnet for cars, there is in fact only one lane for moving motor vehicles. The other two lanes are for parking, on the left curb, and a bike lane on the right curb. So if you can do that there, and if your three neighbor streets all have only one lane for moving motor vehicles, why aren't you eliminating the second motor vehicle lane east of 22nd?

Why Is One Lane Safer? 

Why is one traffic lane so much better than two? Because it reduces speeds and basically eliminates erratic lane changes. 

Let's take a look at a vivid recent example of how this plays out. Dr. Barbara Friedes, a pediatric oncologist at Children's Hospital of Philadelphia, was killed on Spruce street last July 17. 

The driver who killed her, Michael Vahey, swung out of the traffic lane, which was apparently congested, and into the bike lane, which was protected only by plastic flex posts. He put his pedal to the metal, drove over the flex posts, and was apparently going more than 50 mph when he hit Dr. Friedes from behind. It's highly possible that she was unaware she was about to die until he hit her. 

Vahey was performing his special version of a traffic maneuver that drivers perform all the time on multilane streets and highways: jump to the left or the right, depending on where you're starting, and then stomp on the accelerator. It's called passing. Such a maneuver can be performed safely, but safety requires caution and a high level of situational awareness, two things that are not always present in a motorist.

Tree pit, Lombard street.

Denying the motorist a second, or passing, lane will largely eliminate this behavior. It also will reduce average speeds of motor vehicles on the street, because, on a one-lane street, the fastest speed is set by the slowest driver. There's no way around someone who's driving the speed limit. On a multilane street, the fastest speed is set by the fastest driver - the Barney Oldfield of the crew.

I do understand the attraction of driving fast. I was a boy in America in the fifties and the sixties. I read Road & Track and Car & Driver. Among my childhood heroes were Dan Gurney, Stirling Moss, and Juan Fangio. My father, on the other hand, was partial to - yes - Barney Oldfield, and also Wilbur Shaw.

I have said goodbye to all that. Others still cling to the romance of the open road. I think they need to be guided gently onto the paths of righteousness by appropriate design of our streets. 

South at 15th.

See also Defense Doesn't Win Wars; Running of the Bulls on Lombard Street; Willoughby Avenue, Fort Greene, Brooklyn; Is It a Curve or Is It a Turn?