The Ambiguous Hump

How about an ambiguous hump to start your Valentine’s Day ?  Pedestrian / street interfaces in Sydney are needlessly inconsistent. When is a Speed Hump (Speed Table) also a Pedestrian Crossing? When is a Pedestrian Crossing also a Speed Hump? When the traffic engineer felt like it.

Walking about Sydney, we see all sorts of cases. I propose a simpler rule: All high demand pedestrian crossings should be speed humps on the road (the should rise to the sidewalk level). All low demand roadway/sidewalk crossings should be speed humps so that these road and especially  laneway (alley) crossings extend the sidewalk across the road (so the pedestrian is not lowering themself crossing the street, but rather the car is slowing and rising while crossing the sidewalk). I have photos illustrating good, bad, and ambiguous examples from Sydney.

A midblock raised crosswalk/speed hump at the busy entrance to the Broadway Shopping Center. This is excellent, and cars reluctantly yield to the dominant pedestrian. The walk leads to escalators. (Mid-right)
A midblock raised crosswalk/speed hump at the busy entrance to the Broadway Shopping Center. This is excellent, and cars reluctantly yield to the dominant pedestrian. The walk leads to escalators. (Mid-right)
A raised sidewalk across a laneway (alley) at Broadway Shopping Center. This is also excellent, and should be ubiquitous at every laneway in Sydney. The pedestrian is giving me the side eye for taking his picture, but he is important to illustrate traffic safety.
A raised sidewalk across a laneway (alley) at Broadway Shopping Center. This is also excellent, and should be ubiquitous at every laneway in Sydney. The pedestrian is giving me the side eye for taking his picture, but he is important to illustrate traffic safety.
Raised pedestrian crosswalk in Cronulla
Raised pedestrian crosswalk in Cronulla. Similar to the first example at Broadway, but a much less trafficked intersection, with a too narrow bikelane on the side. The sidewalk comes down to the street before the pedestrian rises above the street, and then returns to grade before the next accessibility ramp. Not quite an elegant solution.
Redfern Station Entrance. There is no marked crosswalk, much less a speed hump or raised sidewalk here, despite the huge demand. There is however a speedhump just to the east (left) of the picture for some reason. A missed opportunity. No marked crosswalk means pedestrians must yield to cars.
Redfern Station Entrance. There is no marked crosswalk, much less a speed hump or raised sidewalk here, despite the huge demand. There is however a speedhump just to the east (left) of the picture for some reason. A missed opportunity. No marked crosswalk means pedestrians must yield to cars.
The intersection of Abercrombie Street and Cleveland Street in Darlington (Chippendale is across Cleveland) sees a speed hump on Abercrombie between Hudson Street (the lower right) and Cleveland (upper right). Pedestrians are continuously crossing in this stretch, but the speed hump aligns with neither unmarked crosswalk. Still, it's begging for pedestrians to use it, and they do.
The intersection of Abercrombie Street and Cleveland Street in Darlington (Chippendale is across Cleveland) sees a speed hump on Abercrombie between Hudson Street (the lower right) and Cleveland (upper right). Pedestrians are continuously crossing in this stretch, but the speed hump aligns with neither unmarked crosswalk (at Hudson/Abercrombie nor Cleveland/Abercrombie). Still, it’s begging for pedestrians to use it, and they do.
A signalized but porkchop-islanded crosswalk at a Free Left (Free Right for those in the right-side drive countries). Notice the pedestrian light is red (don't walk) but the pedestrians cross anyway. If the free left is not eliminated in a more comprehensive redesign, it could easily be de-signaled and the crosswalk raised, so pedestrians dominate, and cars travel when they can.
A signalized but porkchop-islanded crosswalk at a Free Left (Free Right for those in the right-side drive countries) (Broadway and City Road). Notice the pedestrian light is red (don’t walk) but the pedestrians cross anyway. If the free left is not eliminated in a more comprehensive redesign, it could easily be de-signaled and the crosswalk raised, so pedestrians dominate, and cars travel when they can.
This speed bump does not want to be mistaken for a pedestrian crossing, so it is landscaped whereever a pedestrian might think of crossing. This is just before the actual intersection, on an extensively calmed street.
This speed bump in Alexandria Park does not want to be mistaken for a pedestrian crossing, so it is landscaped wherever a pedestrian might think of crossing. This is just before the actual intersection, on an extensively calmed street. Cars race from calming device to calming device, treating the chicanes the way a skier might.

A puzzling palimpsest of perceived precepts

The lanes on Riverside Avenue in Minneapolis are now a puzzling palimpsest of perceived precepts. Since the snowplows scraped up some of the most recent markings and whatever obscured the previous iteration, Riverside is now not a self-explaining road, instead it is a self-confusing road. Is there or is there not a turn-lane?
Riverside-thumb-400x533-37663
Photo taken at intersection of Riverside and Butler Place.

Open House for Franklin Ave/East River Road Intersection | Bridgeland News

I attended the Open House for Franklin Ave/East River Road Intersection, where the County and consultants revealed their plans. These are described in the (what I thought was defunct) Bridgeland News article.
My views are here.
In short, instead of a Monderman-esque Shared Space, or even a roundabout, they are tweaking the signal timings and reconfiguring the approach lanes. The main change there is on the Franklin Avenue bridge, which will reduce to 1 lane in each direction on the west side, and flare to two lanes at the approach. This will no doubt improve things (in terms of vehicle delay from most approaches and pedestrian delay) over the baseline, and at least it is relatively cheap, but this, as they officials admit, is a short-term fix, and the intersection will need to be revisited post-Central Corridor.

Comments on Long-Range Funding Solutions Symposium

A Political Economy of Access: Infrastructure, Networks, Cities, and Institutions by David M. Levinson and David A. King
A Political Economy of Access: Infrastructure, Networks, Cities, and Institutions by David M. Levinson and David A. King

On June 24th, MnDOT held a “Long-Range Funding Solutions Symposium” to examine issues associated with the long-term funding of transportation. I was asked to be a discussant. These are my comments in extended form.
Thank you for giving me the opportunity to discuss the topics raised today.
First, MnDOT has identified $50 Billion of unfunded “needs” for additional resources of which 86% are for the purpose of “mobility” over the next 20 years. I am not clear as to how these needs were identified, but several points should be kept in mind. First, this is a slow-growing region (and outside the Metro a declining state). It has 5 million people now, and at best is growing at about 1 percent per year. Second, per-capita Vehicle Miles Traveled has been flat for almost a decade, and overall VMT growth has been flat for about half a decade. There are several reasons for this, most recently recession and high gas prices, but I think the most important is market saturation. if speeds are not growing (because we have maxed out the network given current technologies and face diminishing marginal returns to new road construction), and people have finite time, they choose not to devote additional time to travel (and thus distance). Fortunately, since the I-35W Bridge Collapse, MnDOT has adopted a “fix it first” approach, so that system preservation, operations, and maintenance get the largest share of the existing budget, and comprise the first funded element of needs.
We cannot know what “needs” for mobility are if we have an unpriced (or underpriced) transportation system. People will always over-consume if they are subsidized, and people do not presently pay for the congestion externality they impose on others. Once we have something like marginal cost pricing (or a second-best version thereof), we can determine which links generate more revenue than they cost to operate and maintain, and that will signal where capacity should be added, where the benefits of added capacity outweigh the costs.
Another way of thinking about what $50 billion means is that Minnesota is a state of 5 million people, so that amounts to $10000 of new construction for each resident of Minnesota (because this is above and beyond the funded part which takes care of preservation (we hope)). Over 20 years, $10000 per capita is $500 per year, or about $0.50 per trip. But that $0.50 per trip is not to pay for existing infrastructure, that is to pay for new infrastructure those travelers may or may not use; or if we were to charge users, we would be looking at 10 to 100 times as much per trip, as the new capacity built for $50 billion will serve only 10% to 1% of trips, most trips will continue to use pre-existing infrastructure.
We could also talk about mobility vs. accessibility, and why is it important to enhance mobility, but that is another long discussion, and the reader is referred to the Access to Destinations study for details.
Attention is a scarce resource, spending time on non-starters like $50 Billion in “mobility” needs detracts from real problems with existing infrastructure.
In short, the $50 Billion suggested comprises Wants not Needs. (as Jim Erkel calls it the Rolling Stones theory of transportation finance … You can’t always get what you want, but you get what you need).
Second, we need to re-examine the institutional structure of transportation funding and administration. We should consider a public utility model where a transportation authority or utility with independence from the legislation and executive branch of government determines how much is required to maintain (and as necessary expand) the transportation system, with oversight from a Public Utility Commission or similar. This would resemble how Natural Gas and Electricity and Water and Sewer in many places are currently delivered. Like those, transportation is a utility that has costs that users should bear as directly as possible. The user fee notion would be embedded into the governance structure of such a transportation authority. The British might call this a Transportation Trust. We could consider how this is organized at different levels of government (keeping state and local separate or bringing them together?)
Third, Value Capture has not been fairly characterized in the presentation made today. If we do not have road user fees, transportation creates value for land-owners. (If we do have marginal cost user fees, a closed system, and invest the revenue in transportation, making some simplifying assumptions, we would not have additional land value associated with investment (in the absence of agglomeration economies)). Since we do not have road user fees, value is created. Several of the methods proposed by the value capture study hold promise for financing transportation systematically, not just at the project level.
Fourth, in the short-term (next decade or so), gas taxes, indexed and adjusted appropriately should be used to fund transportation, as they are administratively much more efficient than road user charges. They have several advantages: foremost they are cheaper to collect than most of the proposed VMT charges. An annual odometer reading is certainly a similar alternative, but that does not have the environmental benefits of discouraging motor fuel consumption and encouraging better mileage. Ultimately as the fleet becomes electrified, the gas tax becomes a better and better incentive to move in that direction. If today 100% of the drivers use gas and pay for 100% of roads (which I recognize is not strictly the case at the state level, but is simply illustrative), and next year only 50% of drivers used gasoline, the remaining 50% would pay for all of the roads by doubling the gas tax. That provides a somewhat stronger incentive to switch to electricity. If the following year another 25% switch to electricity, than 75% use electric and 25% use fuel and pay the motor fuel tax, which is now 4 times as high. Eventually this becomes unsustainable as the last drive of a gasoline-powered car could not possibly afford 100% of the road system’s costs, but in the meantime the incentive works in the right direction for the environment, and since government is always a lagging indicator, retaining the gas tax for as long as tenable should be considered the near term solution, with continuing research into road pricing, additional demonstration, and deployment of select strategies like High Occupancy Toll lanes. See Beyond the gas tax for a further discussion.
At any rate, as I have learned today, in Minnesota transit funding depends on the Motor Vehicle Sales Tax, so I will do my part to help fund transit and buy a car.

County presents scenarios for Franklin/East River Parkway remake | Bridgeland News

From the Bridgeland News: County presents scenarios for Franklin/East River Parkway remake
From the article:

“Two suggestions bordered on the Swiftian: One was a modest proposal to remove all traffic control from the existing intersection. “When those signals are out, that intersection functions fairly well,” stated one man.”

I was “one man”.
The official alternatives are available here:
Project website
My letter (sent to the team and local public officials) clarifying what I am thinking about, which I sent to the project team is below:

Jim,
Thank you for hosting the public hearing on the Franklin Ave/27th Street/East River Road intersection. I mentioned the meeting you should consider a shared-space concept (including perhaps a simple roundabout, but without all of the complex signage, separation, etc.) , the ideas I have in mind are illustrated here:
http://www.shared-space.org/
The advantage is that it could cost much less, and could be easily tested (put some covers on the signals, take down the signs, and put up some warning signs telling people upstream they are approaching a new environment, without requiring full reconstruction.
A video showing some of the ideas is here:

AND

(especially at 5:00 into the second video)
I recognize the idea may appear radical to traditional engineering practice, but I think it is worth giving full consideration to, especially on a site like this with no obvious inexpensive solution, with a mix of commuter and parkway traffic, bicycles, and pedestrians, a desire to minimize land taking, and a desire to calm traffic.
Please let me know if you have any questions.
— David

Finally, in addition to having a personal interest in the intersection since I use it daily, I also supervised a Master’s Degree paper: Evaluation of a Roundabout at a Five-Way Intersection: An Alternatives Analysis Using Microsimulation on the intersection by Reuben Collins, which recommended a roundabout.
Unfortunately, judging by their response to comments, the study team clearly has not yet grokked the possibilities of alternatives to conventional (i.e. US standards-based) design, and intends to overbuild and oversign the location.

Evaluation of the Transportation Effects of the I-35W Bridge Collapse

The Nexus group webpage bringing together our ongoing and completed research on the I-35W Bridge collapse is available here. Evaluation of the Transportation Effects of the I-35W Collapse
Note in particular, several reports (links near the bottom of the page) which document the effects of the bridge collapse, reproduced here:

Zhu, S, D. Levinson, H. Liu, and K. Harder (2008) The traffic and behavioral effects of the I-35W Mississippi River bridge collapse (under review)

Xie, F. and D. Levinson (2008) Evaluating the Effects of I-35W Bridge Collapse on Road-Users in the Twin Cities Metropolitan Region (under review)

He, Xiaozheng, Saif Jabari, and Henry X. Liu (2008) Modeling Day-to-day Trip Choice Evolution under Network Disruption (under review)

I-35W Bridge Collapse Transportation Effects

We have posted some preliminary results from the traffic analysis of the I-35W Bridge collapse here: Evaluation of the Transportation Effects of the I-35W Collapse. The reports are near the bottom of the page. These are currently under review and comments are welcome.

Comments on the Central Corridor

I have written a memo for the University of Minnesota administration outlining my views on the proposed Central Corridor, in particular its course through campus. This is based on my thoughts and a number of meetings with University of Minnesota staff, but reflects solely my own judgment. The download is about 10 MB in .pdf (it includes images).

Download File: Central Corridor

For figures, see the .pdf file above

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Another Minnesota Bridge falls silent

The Lowry Avenue Bridge across the Mississippi has been closed: Minneapolis ‘singing’ bridge goes silent and Lowry Avenue Bridge to be shut down
It always made me nervous driving across, with the steel grates instead of a proper paved roadbed. I am sure it was fine, except I like the illusion of surface under my car, which the steel grates prevented.
Too bad they couldn’t time this with the reconstruction of Lowry Avenuetwo years ago, or have gotten the funding and design in place before they had to close it, so a year wouldn’t be wasted with a closed bridge and no construction. Some of the designs shown on the Strib article (above) look good, certainly better than the I-35W bridge.