Monthly Archives: November 2014

The Folly of Double-Left Turn Lanes

There is a troubling, counterproductive “solution” that continues to be employed for addressing congested intersections – even in communities that are otherwise progressively promoting transportation choice. The “solution” is to add a second left turn lane to an existing left-turn lane when there is a perception that the number of motorists waiting in the single left-turn lane has grown too large.

double left turn lane intersection boulder

Conventional traffic engineering claims that creating a double-left turn lane at an intersection is an “improvement” that will reduce greenhouse gas emissions by reducing congestion. And that a double left turn does not conflict with the transportation plan objective of promoting pedestrian trips.

On the contrary, I believe that double-left turn lanes will INCREASE emissions and will REDUCE pedestrian trips.

Double left-turn lanes cause serious problems for scale and safety for bicyclists and pedestrians, but have been shown to be counterproductive even if we are just looking at car capacity at an intersection. Adding a second left turn lane suffers significantly from diminishing returns. That a double-left turn does NOT double the left turn capacity – largely because by significantly increasing the crosswalk distance, the walk cycle must be so long that intersection capacity/efficiency (for cars) is dramatically reduced.

Cities across the nation are facing severe transportation funding shortfalls, yet at the same time, they are often building expensive and counterproductive double-left turn lanes.

Why? Probably because of the absurdity that transportation capital improvement dollars are in a separate silo than maintenance dollars, and that the former dollars are mostly paid by federal and state grants.  Of course, double-left turn lanes also destroy human scale and obliterates the ability to create a sense of place, but those are much more difficult arguments to make.

A colleague of mine adds that double-left turn lanes are an abomination. He adds that “they are a sign of failure: failure to provide enough street connectivity, so that when drivers do come to an intersection, it is gigantic, so it can accommodate all the left turns that had not been allowed prior to that point. Many trips on extra wide arterials are very short, and involve three left turns: one left turn onto the arterial and one left turn off the arterial: there trips could and should be made on connected local streets.”

How can a city claim it is short on transportation funding when it is building such counterproductive facilities? Double-left turn lanes…

  • Increase per capita car travel and reduce bike/pedestrian/transit trips.
  • Increase GHG emissions and fuel consumption.
  • Induce new car trips that were formerly discouraged (via the “triple convergence”).
  • Promote sprawling, dispersed development.
  • Discourage residential and smaller, locally-owned retail.

Cities need to draw a line in the sand: Place a moratorium on intersection double-left turn lanes and eventually removal of such configurations. Double-lefts are too big for the human habitat. They create a car-only atmosphere.


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State Departments of Transportation: Are They Always the Enemy of Our Communities?

What a fiasco. What a charade…

I served on a regional transportation advisory committee in the American Southeast in the first decade of the 21st century. One particularly meeting – emblematic of so many of the meetings with this particular committee — was extremely tense and emotionally stressful.

At nearly all of the meetings I had been to since I was assigned to that committee a few years earlier, there were hostile exchanges and questions/rebuttals between us local folks and the Department of Transportation (DOT) staff. It was a typical meeting where DOT was laying out their latest plans — for destroying our city.

Ruinous plans are the norm for nearly all DOTs I know of throughout the nation.

At this particular meeting, we had a rather crowded agenda chock full of DOT projects to “improve” our city and otherwise make the city more “safe.”

A typical aspect of my service as both a town planner and a member of this committee is that I tend to be the “lone ranger.” The only one who has the courage and (apparently) the awareness to point out the elephant in the room. At this meeting – so much like many of the meetings I attended — I was the sole “no” vote (out of the 15 members) on 10 of the 11 projects on our agenda that day.

The usual DOT proposals for “improvements” and “safety”: Several new turn lanes. Resurfacing huge roads. Speeding up traffic.

highway multi-lane

The usual plans, in other words, to incrementally move our city toward a strip commercial future.

On two of the projects, DOT wanted to resurface big, multi-lane monster roads. In the committee discussion, I confirmed with the City traffic engineer that these two road segments were way over capacity in size. Only a tiny handful of cars used them each day.

No-brainer candidates for seizing the opportunity during resurfacing to restripe these overweight five-laners to 3 lanes, I thought. As usual, my suggestions were met with derision, scoffs, nervous chuckles and, ultimately, deathly silence. Discussion quickly changed to other “more important” ideas such as adding a few trees or shrubs. No one made a comment about my proposed diets.

One of the items was a discussion about DOT plans to essentially buy the front yard of some folks on the major road to add bike lanes. Taking land was needed to install bike lanes and straighten out the road (which, of course, would speed traffic and reduce safety).

As an aside, the redesign of this road was originally intended to primarily improve safety, but again, we only care about car safety at high speeds, not pedestrians, bicyclists or transit users. And to add insult to injury, the location was next to a large university campus, where there were enormous volumes of pedestrians, bicyclists, and transit users.

In any event, I pointed out that as a long-time bicycle commuter who had traveled that segment of road thousands of times, it was my opinion that it was, by far, the most crucial bike lane installation need in the county — particularly because it was next to a major campus, and the lack of bike lanes was very dangerous because it was a road pinch point where cars drive extremely closely to bicyclists at relatively high speeds.

Even for experienced bicyclists such as myself, that location was exceptionally dangerous.

So I told the committee that while I did not at all support the DOT “solution,” adding the lanes there was essential. I pointed out, hopelessly, that the only reasonable design solution was to go back to the design that was nearly approved a few years ago — to remove one of the three travel lanes and create two-way traffic (one lane in each direction) and turn pockets — essentially creating a very pedestrian-friendly, bike-friendly, neighborhood-friendly, low-speed design. We would then have plenty of room for bike lanes without the need to take two-thirds of a front yard of a home. My suggestion was met with silence and the topic quickly changed to something like…oh, I don’t know…the paint color to be used on the road signs.

Another aside: it should be noted that DOT staff always gave the citizen advisory committee pure engineering drawings. In other words, drawings that contain a vast, complex web of hundreds of solid and dashed lines and dimensional measurements that are completely irrelevant and undecipherable to a lay audience trying to make a decision about the project. As in meetings past, I pointed out at the meeting that it was completely impossible for me to figure out anything about what was being proposed on most of the projects. The drawings were a cluttered, jumbled mess.

If DOT was seeking to hide what they were doing on the projects, the drawings they gave us were a perfect way to do it. For several of the items, I began the conversation by asking DOT to tell me, in plain English, what on earth they were proposing, since I had spent days unsuccessfully trying to decipher the packet we’d been given. On a number of the drawings, I had no idea what was being proposed. And I’m a professional town planner. Even the City traffic engineer had to ask DOT staff at the meeting what was being proposed on a few of the drawings. One certainly has to wonder if DOT deliberately gives the committee engineering drawings knowing that only geeky engineers could make heads or tails of what is being proposed.

The committee was an embarrassing joke, and I made that known to my planning department supervisors a number of times since being appointed (asking my supervisors more than once to be taken off the committee). All the committee did was argue heatedly for window-dressing trivialities such as asking DOT for a few more trees or shrubs — all to make driving a car more aesthetically pleasing to the motorist speeding by at 45 mph.

No thought was ever given by this garden club committee to designing streets for functional improvements. No thought or care was directed toward the needs of pedestrians, bicyclists, or transit users — in part because there was very little knowledge of what those sorts of travelers needed. But all of us sure knew how to design for faster driving by a Ford sedan, though…

And DOT staff regularly became quite defensive about their projects, or said the trivial little landscape things asked for were “outside the scope of the project.”

Sometimes, though, their proposed destruction of the city was obvious even to them, and they would ease their guilty conscience by throwing the city a few more trees into the project to put a band-aid on their latest atrocity.

It was a complete waste of my time.

And humiliating, because just by being there, I was implicitly and erroneously sending a message that I thought the items that were pushed by the majority of the committee was anything more than insignificant.

I came to learn that it was a waste of time to make motions for functional and effective design strategies, since I was never able to even get a second to a motion.

Gotta get back to arguing for another crape myrtle…

And to add extreme insult to all of the above, it was announced to the committee during the meeting that  the fearless governor at the time, had a few hours earlier just signed legislation which allowed DOT to exempt itself from local rules. “No stinkin’ local regs are going to stop us from ramming a freeway through your town, boy!”

One has to wonder what point there would then be to having a “design team,” or even a regional transportation planning organization made up of local elected officials. Now even the nearly meaningless landscape and sign rules of the local community could be ignored.

DOT already had the defacto power to trump local laws. Now it was official. I wondered if they were going to even tell us locals about their plans to “improve” our roads in the future, before their bulldozers show up…

As Andres Duany has pointed out, state DOTs have been more destructive of southern cities than General Sherman and the Union Army during the Civil War…

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