Monday, August 28, 2017

No Turn On Red

Vision Zero Meets the South Street Bridge

Sunset Avenue Pavilion, Asbury Park.

Worst things first. The intersection at 27th and South, at the foot of the South Street bridge, presents ... some issues. The worst of these is the traffic that comes off the bridge and turns right to go on to Schuylkill Avenue. I understand that the City's traffic engineers want to get these darling motorists home and in the arms of their loved ones as soon as possible. But perhaps it would be wiser - shall we say more balanced - if they tarry at the light for a few seconds. There's a lot of pedestrian traffic on this bridge - much of it crossing with its back to the turning traffic. And there are various vehicles - both motorized and unmotorized - that come down 27th, cross South, and seek to go down Schuylkill Avenue.

I was there Thursday afternoon, August 24, and I saw three near misses in one hour.

If Vision Zero means anything in this city, it means a No Turn on Red sign at this intersection. Not next year. Not sometime before the next mayoral election. Right now. Make the call, Jim Kenney.

Okay, so let's back up. Why was I out there? Well, a little while ago I posted an article about the westbound traffic on the bridge, suggesting that the traffic that backs up Lombard Street in the morning rush might be alleviated by putting traffic lights on the Schuylkill Expressway. And it got me thinking again about the eastbound traffic. My main concern for the last few years has been the garage entrance for the new CHOP building.

No longer. The worst spot eastbound is the intersection at the eastern foot of the bridge.

Early Friday morning, the South Street Bridge at 27th.

There are other issues, but again, let's back up a bit. I went to the bridge three times in two days and did traffic counts.

A Few Surprises
On Thursday morning, August 24, between 10:45 and 11:45, there were 439 motor vehicles in the left lane crossing the intersection and proceeding east on South Street. In the right-turn lane, headed for Schuylkill Avenue and points beyond, there were 178 vehicles. Of these 178, ten changed their minds at the last minute, swerved across the bike lane, which at this point lies between the two car lanes, and proceeded eastward down South. (Total cars = 617.)

On Thursday afternoon, between 4:50 and 5:50 p.m., there were 370 vehicles in the left lane, heading east on South. There were 301 vehicles in the right-turn lane, heading to Schuylkill Avenue. Of these 301, 13 changed their minds and jumped over to South Street. (Total cars = 671.)

On Friday morning, August 25, between 7:50 and 8:50, 410 vehicles used the left lane to get to South Street. In the right lane there were an additional 201, with ten of those bolting to the left and proceeding down South. (Total cars = 611.)

The totals for each hour are similar, but the composition varies. The highest number of vehicles proceeding down South was on Thursday morning; the highest number of cars using the right lane was on Thursday afternoon.

My main learning here is the number of cars switching from the right lane to the left, and crossing the bike lane to do so. This follows the crossover, where the bike lane moves to the left and the right-hand motor-vehicle lane moves to the curb. This crossover is challenging in itself, but at least people are aware that it is going to happen. What they are unlikely to anticipate is that, approximately every five minutes, a car will cross the bike lane to get from the right lane to the left.

I think the current lane configuration at the east end of the bridge is fundamentally flawed, and not fixable by palliative measures. We need to see people as they are, not as we would have them be, and then we need to design accordingly. A human factors engineer in a good mood could write a very amusing report about this intersection in its current state.

Also observed but not recorded were several u-turns, a number of drivers violating the bike lane near 27th by moving from the left lane to the right and then proceeding to Schuylkill Avenue, and a number of cars stopped in the bike lane. It might be helpful if CHOP management urged its employees to pick up their Uber rides on Schuylkill Avenue, and not on the bridge. Finally, traffic in and out of the CHOP garage was light at all times.

Kill the Turn Lane; Add a Lane Westbound
My initial thought in doing these traffic counts was a desire to free up space for an additional westbound lane on the bridge. As it now stands, the westbound traffic on the bridge starts in one lane, which eventually blossoms into three. If westbound traffic backs up into the single-lane area of the bridge, which it frequently does in the morning, then traffic can quickly back up Lombard as far as 22nd Street. Adding a second lane here would allow westbound and southbound traffic to flow through, avoiding the queue for the northbound Schuylkill ramp.

I don't think adding the second westbound lane would solve all the problems here - the basic problem is the Schuylkill Expressway - but I think it would be a substantial help.

So should we kill the eastbound turn lane and add a westbound lane? Well, I'm for it. It would allow the eastbound bike lane to stay at the curb, avoiding both the crossover area and the bandits who violate the bike lane near the intersection. A No Turn on Red sign would make life much easier for the many pedestrians on the bridge, and overall the intersection should become much calmer. And the snake of traffic that we see so often on Lombard Street should become much shorter and appear less frequently.

The downside is that eastbound traffic will back up much further than it currently does. My observations at the end of August revealed plenty of back-up room on the bridge. It's true that traffic will be heavier after Labor Day. Perhaps someone who gets paid to do this stuff would like to go out and see if numbers from the fall invalidate my basic thesis, which is that there is room on the bridge to queue more cars, and that the bridge is a more appropriate location than Lombard Street.

Beyond that, however, is the question of safety. The current mayor has announced his commitment to Vision Zero. I believe my proposed configuration on the bridge would substantially increase safety for all bridge users. So, tell me how keeping things the way they are fits in with Mayor Kenney's commitment to Vision Zero.

See also Put Traffic Lights on the Schuylkill Expressway and Morning on Lombard Street.

Tuesday, August 15, 2017

Broad Street Cycle Track

This was originally posted on the Facebook page of the Bicycle Coalition of Greater Philadelphia on June 4, 2014:

Just to be truly radical for a moment, what about a cycle track on Broad Street in the median? We could also add parking lanes next to the cycle track, so that vehicular traffic would be reduced to one lane north, one lane south. These parking lanes would become turn lanes at intersections. The parking lanes lanes next to the sidewalk could then be more heavily dedicated to delivery and drop-off.

Sunday, August 6, 2017

Put Traffic Lights on the Schuylkill Expressway

Waiting patiently for a green light on the South Street bridge. 

This idea came to me on July 6 of this year. It had taken me a while to get there. Last year I wrote a story called Morning on Lombard Street, which described the hellacious mess that Lombard Street can become during the morning commute.

On a bad morning, traffic can back up Lombard to 22nd. It turns out that this congestion has essentially nothing to do with the bike lane, although people continue to mention that possibility to me. The congestion is caused by the Schuylkill Expressway. When it backs up heading north, the northbound access ramp from the South Street bridge backs up and then the bridge backs up. If it's bad enough the backup goes across the bridge and then snakes back up Lombard.

If you'd like more of the nitty-gritty on this, read Morning on Lombard Street.

I'd never actually taken pictures of these backups, so last Friday, August 4, I went out in the morning to snap a few shots. It being a Friday morning in August, traffic was very light, and I found myself more interested in another phenomenon that many people seem blissfully unaware of. Cars do not own the South Street bridge. There are scads of bikes and pedestrians and dogs. I'm actually thinking of setting up a coffee stand on the bridge, just next to the northbound ramp to the Schuylkill. And I'll definitely include a free doggie water bowl.

On July 17 there was a community meeting about upgrades to the Lombard and South Street bike lanes. I'd been aware that there was a lot of bike traffic on the South Street bridge - Lombard feeds the westbound bikes onto the bridge, and South takes the eastbound bikes off the bridge - but I was actually surprised to learn that 15 percent of the vehicular traffic on Lombard is bicycles. Then you need to add in the pedestrians, and of course the dogs.

The South Street bridge is not an urban wasteland of concrete and cars.

Six people and a dog in search of a green light.

Even though the car volumes weren't there on Friday, it's interesting that the northbound access ramp still accounted for the lion's share of the cars, as it does on heavier days. The picture below gives you the idea. Westbound and southbound are running clear. The northbound ramp traffic is backed up almost to the CHOP building.

Do not take pictures while walking in a crosswalk.

Here's another shot, showing the Achilles heel of the whole thing. If the cars back up any further than this, you're into the area where there's only one lane. And that means that all the westbound and southbound traffic gets snarled up with the northbound traffic. And some days the snarl goes back up Lombard to 22nd.

The Achilles heel.

Last year, in Morning on Lombard Street, I recommended closing the northbound ramp. Among other things, it's a very dangerous place. You need to enter the Expressway in the fast lane, and the sightlines are not good. People with long experience in this matter told me that my proposal was not new and would never happen.

So here I am with another idea. I recently read that Market Street and JFK Boulevard were designed as "urban highways." They have traffic lights. Instead of treating the stretch of the Schuylkill around the South Street bridge as an interstate, let's call it an urban highway. It doesn't have cross streets, but it has scads of exit and entrance ramps, and the access ramps are pretty much all problematic. Let's put lights across the main roadway and also at the front of each access ramp. Then let people take turns. I'm thinking things will go  better.

When traffic is heavy, something close to this already happens on an informal basis. The cars in the main roadway slow down, and every once in a while they actually let someone in from one of the access ramps. I'm just suggesting that we use familiar, approved traffic control devices to formalize this dance, reducing the danger and frustration that are endemic to the current arrangement.

Waiting at the light by the Schuylkill access ramps.

Let me close with one last picture - I am a bicycle guy after all, and I believe there are more bicycles than cars in this picture. I've been waiting three years to see that. The future is here. It's on the South Street bridge. We just need our village elders to snap out of their Rip Van Winkle act and help us build upon what we can already see with our eyes.

See also Intermittently Terrifying.

Wednesday, August 2, 2017

Balkanized Politics

The Dependent Probability Trap

Esplanade by Fairmount Water Works
I suspect that the balkanized politics of Philadelphia has its basis in neighborhood resistance to urban renewal. What better way to stop unwanted change than to devolve power from City Hall to a series of small community organizations, any one of which can stop any change.

I'm afraid I don't know enough Philadelphia history to be able to prove this case; perhaps someone else can do that. What I do know is that Philadelphia politics is currently well designed to stop just about anything from happening.

And I'm going to show you how it works. Say you have a bike lane that is essentially the backbone of a citywide network of bike lanes. Say it runs through the bailiwicks of three registered community organizations. Say you want to make some improvements to the bike lane.

And here's what happens. The local city council members put their heads together and decide that they're okay with the plans, but that all three RCOs need to hold community meetings and get neighborhood approval. Everybody has to agree.

Let's say that your chances of RCO approval are actually pretty good - say 0.8 on a scale of zero to one.  But your job is to get all three RCOs to agree. And here we run into what I call the dependent probability trap. The probability of getting all three RCOs to agree is not 0.8. It is 0.8 x 0.8 x 0.8. Which is 0.51, or fifty-fifty. Add one more RCO and it is 0.40.

The only way out of this trap is for our elected officials to engage in something called leadership. They need to stop giving their constituents a veto. They need to listen carefully, take counsel, and then make decisions.

It's a much harder job than just ducking for cover anytime a decision looms on the horizon. But it is the job we pay them to do.