Last week Monday Magazine reported on the proposal by johnsonstreetbridge.org inviting the city to conduct a 2-lane bridge experiment to see if the Johnson Street Bridge would work with a lane reduction.
It's something I've written about before on the blog or posted on my website at johnluton.ca and it has been evaluated extensively by city and consulting engineers. The Monday article covered the proposal without any reference to alternate voices that might question the instant expertise of the bridge preservation campaign. Certainly there is no evidence suggesting that campaign organizers have any experience or any record with respect to designing traffic systems or facilities to support cycling. The proposal is a little more elaborate than the "can of paint and a bucket of cement" idea they had several months ago, but it is no less simplistic and so far, hasn't found any support among traffic engineers (structural engineers aren't the same thing).
I wrote and overly long response, knowing that it would not be published of course, but the issue is a lot more complex than a few paragraphs are likely to cover, so here's my take on the issue (again), along with some illustrations that should help understand some of the challenges of the proposal and the comparisons made to other "road diet" projects.
The Johnson St. Bridge and the Burrard bridge are indeed, both bridges, but after that the similarities between the two are overstated. As a model for the wishful thinking of those who have convinced themselves that a 2 lane scheme is a simple and inexpensive solution in service of saving the Blue Bridge the comparisons just don't add up.
That "solution" has been studied for a decade and has been found wanting by most in the cycling community and every qualified engineer that has examined the structure of traffic carried by the bridge.
The Burrard St. bridge bike lane project took out 1 of 3 lanes, not 1 of 2, a pretty significant capacity differential that is key to the functionality of the transportation network supported by the Johnson St. Bridge. There are also 3 lanes running in the opposing direction on Burrard, though irrelevant to traffic flow, is still critical to the level of service provided to emergency vehicles, an important function of any bridge.
South of Burrard, traffic bottled up on the bridge by the lane reduction has several exiting lanes to relieve congestion and sustain flow. At the north end, there is generous "storage" capacity on Burrard and more on Pacific where queuing traffic can wait for the signal cycle that will channel them through the network. There's also additional capacity available at Granville for vehicles heading into a larger downtown and it too is absorbing some of the traffic diverting from Burrard.
At Johson St. the "goldilocks" point where capacity and demand meet is at Tyee and Esquimalt, not on the downtown side. Traffic volumes of around 25,000 vehicles a day (ADT) are destined to or from Tyee (8,000 ADT), and Esquimalt (18,000 ADT). On the downtown side there is no surplus storage that compares with Burrard. Queues will back up through Pandora at Store and across Yates on Wharf. Intersections further upstream may also experience gridlock, more certainly when the bridge is up (something that doesn't happen, of course, on the Burrard bridge).
Bay St. is not an alternative for Johnson St. Bridge traffic. It's maxed out now and can't provide more capacity. Ad nauseum calls for four laning are stillborn. Where is the road capacity on either side of the bridge to absorb additional traffic on the bridge (Ralmax, Westside Village?), and what would that downtown destined traffic do to gateway streets north of the city centre?
Gains for cyclists are also exaggerated. The physical separation afforded cyclists on the Burrard bridge eat up a lot of space that just isn't available on the Johnson St. bridge. The 1.5 meters that works on a road bike lane is too narrow on a bridge where lateral obstructions reach elbow or shoulder height and there is no room for physical barriers of any sort between the bike lane and traffic that includes frequent bus service and numbers of truck movements. Routing to and from the Goose would remain as convoluted as ever. The better signage proposed by some critics is truly "lipstick on a pig".
The 2 lane fairy tale is a loser for cyclists, as well as for pedestrians and people with mobility challenges. The levels of service can't compete with the purposeful designs that can be incorporated into a new bridge. Along with the real numbers on costs and the challenges posed by the staging of works - rehab means extended closures and serious economic impacts for downtown - citizens of Victoria have a lot to think about as they evaluate the options they would like council to consider.
The campaign to save the old bridge has always clamoured for more information and that's a welcome contribution to the discussion. Every fresh piece of information points to the new bridge as the right choice, and at every step critics clutch at new straws to advance an agenda, which is to preserve the old bridge, not matter how disfunctional or how costly.
For those that are willing to wade through my website or my personal blog, there is lots to read on the bridge from several angles.
Some of the specifics about the bridge and traffic patterns are at: http://www.johnluton.ca/pages/focusanswers.html
Bridge topics are also a frequent theme of my blog at http://johnluton.blogspot.com/
Illustrations of some of the issues can be found at my flickr pages, and a bunch of new pics are up on the page with this one that shows what the bridge is connected to: http://www.flickr.com/photos/luton/4733674188/
While this may be too much for publication, the campaign to save the bridge started out more than a year ago clamouring for more information. I do my best to get it out there. People are free to poke holes in it or take it at face value as they choose, but the facts will be very stubborn.
Everything I've put out there seems to be backed up by engineers familiar with our roads and bridges and with traffic systems design. It's nice to hear from structural and heritage engineers, but they can't provide the comprehensive analysis we need to make sound choices on the future of the bridge.
John Luton, Councillor
City of Victoria
The 2 lane trial petition doesn't seem to be getting anywhere on the jsb.org site: it's stalled out, and is filling up with Russian spam.ReplyDelete
To have 1.5m bike lanes on the bridge is close quarters. I shudder to imaging riding between the bridge structure and a large truck or bus. 1.5 metres is okay for an open space, but, as you point out, with solid barriers at shoulder level, it's not safe. Vehicles often wander in their lanes on this narrow bridge; side mirrors would be lining up with cyclists' heads.
The bridge is only 9 meters wide; there isn't room for physically separated bike lanes. But bike lanes are desperately needed, as either biking the bridge or merely sitting and watching people cross it will attest. The more I study the bridge, the more I see the need for clearly marked, well designed routes for all users.
I understand that emergency services in Victoria have expressed concern that 2 lanes would constrict emergency vehicle access, not a satisfactory result.
Hey John, can you elaborate on the problem with the 4-lane Bay proposal or point me to some more resources? Thanks.ReplyDelete
Hi Jared, I'm a little slow at finding some of the comments. I'm struggling through with my laptop while my new computer gets loaded up after my tech buddy couldn't fix the old one. It's been several weeks of frustration, and September was a busy enough month with a couple of conferences.ReplyDelete
The problem of adding 4 lanes to the Bay St. Bridge is that the bridge does not operate in isolation from the road network it connects to. On either side of the bridge Bay St. is only 2 lanes, one in each direction. At about 20,000 vehicles per day, Bay St. is already near capacity and if the bridge was expanded, the road would have to be widened to add the 4 lanes to match the bridge. Existing industrial and commercial properties on either side would cost tens of millions to acquire, if the property owners were willing to sell. Cities, for the most part, will not expropriate unless for very good reasons, and compensation is still required.
Apart from being so much more costly than simply the bridge retrofit alone, (which itself would be expensive), adding capacity to the bridge would not meet our transportation needs in any event. Bay St. doesn't bring traffic downtown, at least not directly and the competition with industrial traffic would hamper their activities and create other safety issues.
We want to keep what industry we have intact and are not contemplating traffic diversion schemes that would undermine their viability. On the westside, we would be equally challenged by having to slice off some of the westside village shopping centre to increase the capacity 4 lanes on the bridge would be delivering.
You don't need to see more resources, just understand that traffic by nature doesn't stand still, and wherever you add capacity, it has to go somewhere.
For some theory on lane capacity, and it will discuss peak hour flows, which are important to the understanding of what roads need to carry - functionality is critical at maximum demand for travel during afternoon rush hours -see http://www.fhwa.dot.gov/ohim/hpmsmanl/appn3.cfm