FYI, this is not MUTCD approved. Request for experimentation is required.
This post is cross-posted at Streets.mn.
A recent report by researchers Greg Lindsey, Kristopher Hoff, Steve Hankey, and Xize Wang from the University of Minnesota is available for download from the Center for Transportation Studies website here. The report is titled Understanding the Use of Non-Motorized Transportation Facilities, and it is a fantastic read for anyone interested in bicycle and pedestrian counts in the Twin Cities.
The report may be a bit academic for casual blog readers, but it is also surprisingly readable. Even if the discussion of statistics isn’t your cup of tea, anyone familiar with the Minneapolis cycling scene will appreciate that all the data used in this study was collected on local trails at locations even casual cyclists will be familiar with. You’ve probably even seen some of the counting technology on the trail side and may not have known what it was. This report is an excellent and accessible document that will tell you everything you ever wanted to know about bike counts and prediction models in the Twin Cities, including how accurate they are.
The report starts by giving a brief overview of various bicycle and pedestrian counting strategies, then explains which methods are in use in the twin cities (manual, induction loop, infrared).
If you’ve ever wondered how accurate the various automated counters are, take a look at Chapter 3. Turns out (spoiler alert!) that the data collected by the induction loops is all over the place (mean error of 45% at one location), but the infrared counters are pretty reliably undercounting by about 10%*. In addition, the induction loops are only collecting usable data around 80% of the time, while the infrared counters are collecting usable data about 90% of the time.
Infrared: 1 Induction: 0
Oh, and manual counts? About 1.4% error.
Chapter 4 is a smattering of descriptive statistics about the bike and pedestrian counts based on factors such as the presence of a bus line or roadway functional classification. There’s nothing groundbreaking about this info, but it’s certainly an interesting read. For example, the average estimated number of pedestrians on roadways with a bus route is 1,071, but the average estimated number of pedestrians on roadways without a bus route is 547. The report allows readers to draw their own conclusions.
Chapter 5 establishes procedures for creating daily (monthly, annual) bike counts based on a limited amount of field data. The authors calculate scaling factors that can be used to estimate 12 hour bike or ped counts based on only one or two hours of collected data. Here’s the short version: If you can only collect one hours worth of bike data at a location, your best bet is to collect data from 4:00-5:00 PM and multiply the number of bikes you count by 8.4.
They also compared weekend traffic with weekday traffic by creating a ratio (weekend/weekday) to estimate recreational vs. utilitarian trips on the Midtown Greenway. Generally, the ratios ranged somewhere between 1 and 2. The authors roughly associate weekend trips with recreational trips, which is certain to be somewhat true, but this is one of the sketchier assumptions the authors make in the paper.
Chapter 6 is the real meat of the paper (and the real contribution to academia), which develops several quantitative models for predicting bicycle and pedestrian counts based on a host of other measurable variables. You’ll have to read the report to get the full effect, but the result is this graphic, which attempts to predict bicycle and pedestrian travel on Minneapolis roadways and trails:
Readers, please take a moment to review this article if you have an interest in bicycle and pedestrian counts. In the comments section below, I’d love to hear some of your own thoughts about the study.
*Either I’m reading it wrong, or there is an error in the column headings for Table 3.4 (mean hourly manual count and mean hourly TMI count should be swapped)
Pedestrian safety in MN is in the news again with this article from the Star Tribune:
The article mentions a number of new technologies that engineers are using to try to improve safety conditions for pedestrians in crosswalks (which includes cyclists).
I’ve recommended strategies like these to clients on numerous occasions. The clients typically report that these strategies are effective, but of course, most clients do not conduct before-and-after studies to confirm this. The Strib article acknowledges that we don’t know to what extent these devices are effective:
Whether the devices themselves result in a measurable safety improvement is one question. Another question is to what extent the benefits of these products are diminished as they become more widely deployed. Flashing lights at one crosswalk may raise driver awareness because they are unique. If flashing lights were installed at every crosswalk, the benefits of all installations may be diminished as they are no longer unique.
The article also touched on a pet-peeve of mine:
The “false sense of security” theory is largely unfounded, though it is widely repeated. Studies have shown that in certain circumstances, pedestrian crashes are higher at locations with marked crosswalks compared to similar locations without marked crosswalks. However, there is no evidence to conclude that this is because pedestrians are exhibiting riskier behavior where crosswalks are present. It may be the case, but this has not been demonstrated. For more on this topic, see pages 4-10 of this study.
A couple month’s ago, I posted about Portland’s Bicycle Barometer” a bicycle counting system that posted a real-time count on an LED display for passers-by to see.
Today, Cyclelicio.us brought my attention to the (almost) real-time bike counts the City of Boulder has made available online.
Apparently there is some delay in the data being posted to the website, but counts are as recent as 24 hours. At this location, there were 1,307 cyclists counted on October 3, 2012.
This data is available at 13 locations in Boulder, though I can’t seem to find a list of these locations or a link to the data (if anyone can provide this link, I’d be grateful). Also, a bit of Googling suggests that Ottawa is using the same technology.
Minneapolis should have this. We’re already counting bikes 24/7 at several locations, the data should be made publicly available online so long as we are reasonably confident the data is accurate. And if we are not confident, it is worth the investment for better equipment.
I happened to ride past the newly repaved and restriped Park Avenue this past weekend and noticed the new bike lanes have been placed. It’s still a work in progress, but here’s what it looked like as of 10:00 AM this past Sunday.
The first thing that struck me about this new design is just how wide the new bikeway is. I didn’t get out a tape measure, but I’m guessing that this is a Hennepin County standard 6′ bike lane between an additional 4-5′ of buffer space on either side of the lane. This results in what looks like about 15′+ of pavement dedicated to a single bike lane!
Agencies are typically trying to find ways to sandwich narrow bike lanes within constricted rights-of-way. In this case, however, since the County removed one of the travel lanes on Park Avenue, they’re now faced with the opposite problem. What to do with all of this extra space?
Is wider always better? Are larger buffer spaces always better than smaller buffer spaces? Maybe. Maybe not. Bike lanes any wider than about 7′ or 8′ are generally not encouraged because motorists begin to confuse the bike lane with general purpose lanes.
This will be an interesting experiment to see how well motorists respect the bike lanes. Since the bike lane (including the buffer space) is plenty wide enough to function as a lane for motorists, and since there are no physical barriers keeping motorists out of the lanes, I wonder if we will experience problems with motorists encroaching into the bike lane too often.
I’m not sure. This will be an interesting case study to keep an eye on.
What do you think of the new lanes? Have you had a chance to ride them yet?
MPR News has a great article about a MnDOT safety campaign aimed at improving conditions for pedestrians:
I love this MnDOT safety campaign, and I think efforts to modify behavior are a critical step towards improving safety conditions for bicyclists and pedestrians. However, one thing the MPR article didn’t pick up on, but the MnDOT press release made pretty clear, is the increasingly important role of technology. The press release contained a more complete quote from Groth:
As much as engineers are continuously making improvements to roadways, we’re also pretty sure that the lion’s share of the credit for reducing motorist fatalities belongs to the automobiles themselves. Still, campaigns to raise awareness and modify behavior are important.
The Prudent Cyclist alerted me to this video about Oregon’s “Scenic Bikeways”.
I love the idea of developing a statewide network of scenic bikeways. In some ways, we’ve already been doing this for years, since planners and engineers tend to assume that cyclists always prefer scenic (rather than direct) routes. It’s not immediately clear to me how the scenic bikeways idea is wholly different than the U.S. Bicycle Route System that is already well underway (other than the obvious statewide vs. national scope). Minnesota’s first contribution to the USBRS is the Mississippi River Trail, which is clearly intended to be a scenic bikeway, as opposed to filling any sort of utility transportation need. We can reasonably assume that anyone traveling over x miles is doing so primarily for recreational purposes, but there is still some value in developing separate systems for both scenic and transportation bicycle travel, though there is likely to be much overlap.
Cyclelicio.us brought my attention to this contraption:
It doesn’t look fun or convenient. It looks awkward and uncomfortable, a bit difficult, and I want to know what happens when this guy accidentally runs over his own foot with the rear wheel.
I could appreciate this illustration from the wonderfully entertaining blog Bikeyface about some potential new pavement markings engineers could start using to organize and segregate different types of roadway users.
This is tongue-in-cheek, obviously, but the toolbox of available bicycle pavement markings has been rapidly expanding over the past decade. How many markings is too many markings?
Three of the largest national biking advocacy groups announced several months ago that they intended to merge into a single entity. Today, they announced that after more discussion, they have decided to remain separate and distinct entities. They made the announcement by each of the three groups posting identical blurbs on their respective blogs:
An ironic way to declare independence.
I was excited for this merger, mostly because the three groups were similar enough that I could barely tell them apart to begin with. It would mean two fewer organizations to keep tabs on. So many of their press releases were identical already that to get identical content from three different organizations in my RSS reader was a bit annoying.
One wonders if this fell apart because of ideological differences between the groups (perhaps pushback from LAB’s many vehicular cycling advocates?), or if it was simply because the merger would inevitably mean that someone would find themselves redundant and out of a job. It would be hard to argue in favor of any merger plan that leaves you unemployed. Or maybe just a mundane legal issue. I don’t know.
At any rate, it appears we will continue to have to sift through identical content from three different organizations for the foreseeable future. Oh well.
Copyright © 2014 VeloTraffic - All Rights Reserved
Powered by WordPress & Atahualpa