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Archive for the 'traffic' Category

LiveableStreets Alliance

Posted by @teeheehee on 3rd February 2008


Wheel valves

This past Wednesday my rear tire went flat on the way to a LiveableStreets Alliance lecture. My innertube needed to be replaced (the presta valve tip broke off) but the lecture lightened my mood with some interesting information on how roads are engineered.

Backtracking for just a moment, I have had some brushes with LiveableStreets folks before at some other bike events. The group seems pretty solid despite their small size, dedicating themselves to presenting a fresh vision of street design engineered to meet human needs as much as motor vehicular ones. Basically, they’re working to change Boston.

The talk was entitled “Dirty Little Engineering Secrets Revealed,” and it was a powerpoint presentation given by former LiveableStreets Alliance co-founder and president Jeffrey Rosenblum. (Jeff now works for the City of Cambridge, helping their street planning.)

The talk spanned elements of psychology, engineering and design. The dirty secrets revealed were completely expected: there was a whole generation of engineering that devoted itself to the car and that is reflected in street design. This extends into the urban areas and the purpose of the street as a functioning place of commerce and burgeoning life has been replaced with one of traffic and single-minded transport.

When a street is designed there are studies done, stages of planning and review, lots of referencing to standards guides, and usually after all of that is there any public involvement. (Then, of course the street is constructed with whatever variance, no construction job ever goes 100% to plan.)

The studies are generally car-centric. Traffic numbers, connections, types of vehicles and their purposes, types of streets connected, etc. The result of a study is a report a few inches thick. How much of that for bikes? Nil.

The Green Book

The street gets planned following guidelines. The guidelines used were printed with some degree of flexibility which in practice is never used. When challenged why lane widths can’t be made more narrow to accommodate a bike lane they often reference the Green Book, but neglect the flexibility it allows for.

Flexibility in Highway Design

LiveableStreets works to draw attention to that flexibility factor. The current generation of engineers are still following the idea that streets need to be designed to achieve maximum throughput, with multi-lane highways often considered the pinnacle. In urban arenas this does not make sense. The next generation of engineers may have a more modern view but it will take a while for their designs to become commonplace. Political pressure and general public knowledge can help to advance this progress.

Bikes aren’t the only things that lose out to the current models of street design. Pedestrians and anyone with a permanent or temporary handicap are often considered only in the later design revisions. Engineers understand that at any one time a certain percentage of the population will have their mobility hindered and may require more time for crossing, ramps, adequate sidewalk conditions for wheels, and usually as short of a distance between entering and exiting the road as possible. That doesn’t mean design works all of this in all the time.

Highlighting the lapse in thinking with pedestrians in mind was a series of photos of the Longfellow Bridge. On one end there are no crosswalks to get someone walking from one area to the sidewalk that spans the bridge. The sidewalk itself is less than the normal width, and is peppered with obstructions. One argument states there aren’t enough pedestrians using the bridge to warrant improving the sidewalks. This is a backwards argument – if it was a better medium there would be more usage. Realistically the issue here is the same issue with any redevelopment: money.

Along with more flexible engineering there was also an example of a more radical approach which plays much more with social engineering aspects: naked streets (in large part due to late Hans Monderman. The idea here being that you should treat motorists like adults, they’ll know how to react with people walking all around them even with no signs regulating them to be courteous and yield. Intersections with no signs, which makes motorists behave differently. The result: rational decisions are made by all street users.

There was more in the talk and the discussion that followed. Time was up and I was left wanting more so I hope there will be other presentations in the future. The more we know about the limitations, the more we can maneuver within them.

Posted in bike friendly, traffic | 2 Comments »

We use tools to help us

Posted by @teeheehee on 29th January 2008

Recently I marginally helped an intriguing venture to assess several Boston roads for possible bike lane inclusion. I wish I could have spared more time to the effort, and I guess I’m not the only one saying that since in a little over a month’s allotment only 16 of a desired 50 roads were surveyed. This was work spread out over several individuals who volunteered, and of which I probably helped the least or near least. (I’d offer excuses, but this is a bike story, not a work-woe story. If you need to ask: woe is work.)

The idea behind the activity was to find out what roads are already wide enough to support a bike lane, with particular preference to roads that connect any other already-established bike networking routes or major areas of the city. Ideally some roads are already wide enough to include a bike lane, and those would be cheapest and fastest for the city to adapt. The survey work involved detailing any observations from a biker’s point of view, such as metal plates in the road or incorrect alignment of gutter plates, as well as measuring road cross-sections with one of these:

Measuring wheel

The wheel I was loaned took measurements in .12″. Everyone else’s read in .10″. I have no idea why the wheel I used was any different, nor what the significance of .12″ is (anyone care to fill me in?), but that’s what I had to walk across the road many times with and note the distance of the center of every line of paint (parking, white lines, yellow lines, etc.) The person who collected all the data we obtained had to write a conversion routine and apply it to all of my collected numbers.

Someone brought up the point of “why do we have to take these measurements, wouldn’t the city already know all of this?” And the answer I heard given started out as “well, ya see…” and sorrowfully explained that the measurements currently available are all too inaccurate to be of much use. Our measurements, as accurate as they can be, still need to account for several inches for error or variance between measured points. We took measurements wherever the road widths changed a recognizable amount, which may be often but not necessarily often enough. Whatever our measurements come out to be will be better than what was there before, and up to date.

I hope that something comes of this attempt, and that we’re not left oggling the void of another action->no-action response from the city. I am disappointed about how little I chipped in for this, but would feel cheated if it all amounts to nothing. Kudos to LiveableStreets for putting up the measurement wheels that we got on loan, and to the Boston Bikes initiative that was all under the auspices of: I hope to be of more use on the next venture.

Posted in bike friendly, safety, traffic | 1 Comment »

Space comparison: bikes, cars, bus

Posted by @teeheehee on 26th January 2008

Bike vs. cars vs. bus. How much space do these modes of transportation take up for the same number of people? Thank you for finding out for us, Muenster.


Muenster space comparison 72 bikes, 72 cars, and a bus

From the site:

  • Bicycle: 72 people are transported on 72 bikes, which requires 90 square meters.
  • Car: Based on an average occupancy of 1.2 people per car, 60 cars are needed to transport 72 people, which takes 1,000 square meters.
  • Bus: 72 people can be transported on 1 bus, which only requires 30 square meters of space and no permanent parking space, since it can be parked elsewhere.

Posted in bike friendly, traffic | No Comments »

Berkeley Bike Boulevards

Posted by @teeheehee on 26th January 2008

I really like the looks of this. This is a good solution to accommodate bicycling and pedestrian needs while calming motorist traffic.

I am left wondering how this could ever be adopted in Boston. Yeah, right.

Posted in bike friendly, traffic | 1 Comment »