Category Archives: facility

Top planning books of 2012…including the Bikeway Design Guide?

Planetizen just announced its 11th annual list of the ten best books in urban planning, design and development published for 2012. The list selected by Planetizen’s editorial staff covers a range of urgent topics. A couple of reactions:

-Popular press and journalistic authors dominate (not academics and researchers). This is to be expected, but I did not recognize a single academic. I suppose our writing style (or our findings?) really are boring.

…but, speaking of boring:

-Of the ten books listed, the 329 page Urban Bikeway Design Guide by the National Association of City Transportation Officials is one of them. Seriously? A technical manual as a “best of”? Apparently, the editorial staff is stacked w insomniacs. It is great to see a bike reference among the list. And, it is a really useful guide, don’t get me wrong. But still.

Heated paths — which first and what of salt?

Snow season is coming (at least in northern places in the northern hemisphere). I have read two accounts in the past week calling for heated bike paths and heated sidewalks.

Heating coils are one option. Retaining summer heat is the other. Both seem pretty expensive. But it does beg two questions, assuming it can be done and paid for,

1. Is it best to start with the sidewalks, bike paths or roads? I am less convinced the roads need it. The cars are relatively stable in moderate snow.

2. Can we really kick the salt habit?

Choking the choke points

For much of the population, a bicycle route is only as good as its weakest link. An average commuter can bliss out for 90 percent of their ride along an off-street path; but if the remaining 10 percent involve a particularly unsafe intersection or a troubling bridge crossing, it could be a show stopper. I call these choke points; they are often thought of as the weakest link in the chain of bicycle facilities for a city.
They represent an often glossed over, but important tenet of bicycle planning; ironically, they are also one of the most difficult to stay on top of. They come in two varieties. We can refer to them as (1) facility disruptions and (2) naturals.
Facility disruption: It’s simple for a city with no facilities to have no chokepoints; the whole city is a choke point. There are no real facilities that end prematurely. The more facilities a city brings on-line, the more likely choke points result. Every new lane or path needs a starting and ending point[1] and unless they are seamlessly woven into the existing fabric, there is likely some discontinuity that will result.
Naturals: Some cities are naturals for choke points. Seattle, comprised of labyrinth of water barriers which serve to funnel cyclists to select routes, is littered with them. In most communities the ordinary constriction of roadway space owing to bridges over railroads or rivers provides good fodder for where chokepoints fester. And, oftentimes the worst choke points are temporary, resulting from detours owing to construction[2], which is probably best labeled a natural occurance.
The best thing a city can do about choke points is threefold: identify, address, and minimize them.
One of the more systematic efforts to address these comes from Minneapolis, Minnesota. As of 2010, they had 54 gaps in their system[3]–one for each square mile of the entire city[4]. What other cities are taking formal and detailed inventory of the discontinuities and reporting on them?

[1] Starting and ending point: Krizek, K. J. and R. W. Roland (2005). “What is at the end of the road? Understanding discontinuities of on-street bicycle lanes in urban settings.” Transportation Research Part D: Transport and Environment 10(1): 55-68.
[2] Choke points owing to construction: Krizek, K. J. (2002). Even Here, A Failure to Respect Cyclists’ Needs. Minneapolis Star Tribune,. Minneapolis: A2 (commentary).
[3] Gaps in the Minneapolis system: see chapter 7 in Pflaum, D. (2011). Minneapolis Bicycle Master Plan. Minneapolis, Minneapolis Public Works.
[4] One gap per square mile in Minneapolis: The city’s area is 58.4 square miles; once you account for the fact that 6 percent of that area is water, it comes to 54 square miles.

2012 Prez of ITE is a bike planner

ITE HomeRock E. Miller is the 2012 president of the Institute of Transportation Engineers. His experience is recognized in a wide variety of specialty disciplines, but he is best known for his work in traffic signal operation and development of enhanced facilities for pedestrians and bicycles.  Rock holds a B.S. and an M.S. from the University of California, Davis, where he participated in early research on bikeways.

Speed for bicyle travel

Knowing reliable measures of urban cycling speeds is helpful for:
-planning various types of facilities (e.g., turning radii),
-traffic flow estimations,
-better understanding the degree to which various users can comply with harmonious co-mingling,
-modelling exercises (e.g., accessibility metrics),
-general curiousity
It is often thrown out there that speeds for cyclists who travel in urban areas hovers about 10 mph. What do we know of this? Any value, we would expect, would have wide variation. A compilation of a bunch of studies prior to 2000 suggested that free-flow bicycle speeds appears to be somewhere between 6.2 mph and 17.4; the majority of the observations were between 7.5 and 12.4[1]. Of course a lot of the variation is explained by which type of facility the data are from.
Some other or follow up work found values of 9.2 mph during a recreational event that included adults and children[2], 13 mph along greenways in Indianapolis[3] and 15.4 mph along a separated path in Denver[4].
Does this vary by city, time of day, or time of week? Hard to say. Studies using similar methods found average speeds in Toronto to be 9.3 versus 11. 6 in Ottawa[5]. The most interesting revelation is coming from some 11.6 million bicycle trips analyzed as part of the Lyon bikesharing system[6]. The average 2.49 km trip took 14.7 minutes—converting to 6.2 mph—much slower than the above values, probably owing to heavier bikes and more congested conditions. They observed some uptick in speeds during rush hour (people are more pressed for time). But here is the interesting nugget: wednesday morning speeds were systematically higher than other weekdays—a phenomenon the researchers suggest might be because of the higher proportion of (faster) masculine bikers, since a significant fraction of women stay home to care for children on Wednesdays.
It looks like 10 mph is a safe and reliable average.

[1] Compilation of a bunch of studies: Allen, D. P., N. Rouphail, et al. (1998). “Operational analysis of uninterrupted bicycle facilities.” Transportation Research Record: Journal of the Transportation Research Board 1636(1): 29-36.
[2] Speed during a recreational event: Thompson, D. C., V. Rebolledo, et al. (1997). “Bike speed measurements in a recreational population: validity of self reported speed.” Injury Prevention 3(1): 43.
[3] Along greenways in Indianapolis: Lindsey, Greg and Nguyen Luu Bao Doan. 10 Questions about use of urban greenway trails. in Paper presented at Southern Illinois Transportation
Alternatives Conference, 2002.
[4] Bike path in Denver: 8. Khan, Sarosh I. and Winai Raksuntorn. Characteristics of passing and meeting maneuvers on exclusive bicycle paths. Transportation Research Record. 1776,
2001: p. 220-228.
[5] Cyclist speeds – see: Aultman-Hall, Lisa and Michael L. Hill, “Characterizing the Personal Attributes and Travel Behavior of Adult Commuter Cyclists”, Proceedings of the Institute of Transportation Engineers International Annual Meeting, Toronto, ON, August 1998.
[6] Lyon bikeshare system speeds: Jensen, P., J. B. Rouquier, et al. (2010). “Characterizing the speed and paths of shared bicycle use in Lyon.” Transportation Research Part D: Transport and Environment 15(8): 522-524.