Monday, December 5, 2016

I’m Back and I Want to Talk About a Road Diet

Petaluma Boulevard South
(note truck using both 10-foot lanes)
Let me start by apologizing for my long absence from this soapbox.  It wasn't a planned absence, although in retrospect it does feel as if it were inevitable.

In my next post, I’ll talk about the reasons for my temporary disappearance after nearly five years of thrice weekly posts.  But today I have a subject of more immediate importance.

I’ve previously written about road diets, modifications to existing streets to readjust the balance between cars, bicyclists, and pedestrians.

The most common version of a road diet, one that has been implemented in communities across the country, converts two lanes of traffic in each direction into single travel lanes, a center turn lane, and, depending on the geometry of the existing street, added accommodation for bicycles, pedestrians, parking, and/or street beautification.  As long as the traffic doesn’t exceed 20,000 daily trips, these “four-to-three” road diets have been found to have little to no impact on traffic capacity.

Wikipedia provides a summary of road diets in the U.S., although the list of completed projects is deficient.

In Petaluma where I live, a road diet was implemented a few years back on Petaluma Boulevard through the heart of downtown and continuing a little further north.  As I described in the post linked above, the project was controversial.  There was significant opposition before construction and many were willing to decry the road diet as a failure immediately after completion.

The debate has largely died away, although occasional pockets of obstreperousness remain.  But by most objective and subjective measures, the downtown road diet has been a success.  Traffic counts are higher now than they were before the road diet, showing that capacity wasn’t harmed.  Traffic accidents are reduced.  Pedestrians generally report a more comfortable experience.  And bicyclists, although still bemoaning the lack of bike lanes which weren’t possible because of the narrowness of the road, admit that the riding experience is better than before. 

Encouraged by that success and motivated by the availability of grant funds that can repave deteriorating streets as a part of implementing road diets, city staff has been alert to the possibility of more road diets.

They identified South Petaluma Boulevard as a suitable project.  The work would begin at the southern end of the previous road diet and continue another mile south.  Indeed, they found that it was the road section in Petaluma that best fit the criteria for a newly announced grant program.  With staff having identified the opportunity, a City Council hearing is scheduled for December 19 to consider giving direction to city staff to apply for the grant.

As a long-time user and observer of Petaluma Boulevard South, I’m pleased with the progress.  The street needs a change.  The roadway segment nearest to downtown has four 10-foot travel lanes and two six-foot parking lanes.  Although there are places where 10-foot lanes can work, and may even be desirable, four 10-foot lanes bracketed by narrow parking isn’t one of those places.  And six-foot parking lanes, compared to more common widths of seven or eight feet, often induce drivers to park with two wheel s on the curb, diminishing the pedestrian experience.

Adding in the aging and heavily patched pavement, the street is an uncomfortable drive for motorists.  It’s even worse for bicyclists and pedestrians, especially for walkers trying to cross the boulevard from the residential neighborhoods south of the boulevard to the restaurants and riverside parks to the north.

Also, Petaluma Boulevard South is the designated multi-use path (MUP) for the SMART train that is coming soon to the North Bay.  The MUP, which was essential to voter approval of SMART, is the route by which bicyclists are directed to reach SMART stations or to tour the North Bay.  It’s an embarrassment to both SMART and Petaluma to have the MUP aligned along a road that is so unwelcoming to bikes.

Despite the logic for the Petaluma Boulevard South road diet, some opposition nonetheless arose, offering many of the same arguments that were used against the downtown road diet, largely focusing around traffic capacity.  And there were indications that some Councilmembers might pay heed to the opposition.

Anticipating this resistance, a group, to which I belong, came together to argue for the road diet.  We’re currently walking door-to-door in the neighborhoods that are most likely to be benefited by the road diet, educating the residents about the benefits of the road diet and asking for their support.

This is where the readers come in, at least those readers who remain here after my three- month sabbatical.  If you live in or near Petaluma and believe a road diet on Petaluma Boulevard South might be a great idea, I have three suggestions for you.

1) You can attend a question-and-answer session at the Aqus Café, 2nd and H Streets in Petaluma at 5:00pm on Wednesday, December 7.  Thus far, city staff hasn’t committed to participate, but others can hopefully answer any questions you might have.

2) If a road diet still sounds like a good idea, you can visit to share your opinion with whichever Councilmembers you select.

3)  Lastly, you can attend the Council meeting on Monday, December 19 to express your views.  Or at least to show a common purpose with those who will be attending to support the road diet.     

This isn’t the last time I’ll write about road diets between now and the Council hearing.  In particular, I’ll let a friend, professional planner, and bicycling advocate use this space next week to more fully explain road diets.

But this introduction will hopefully suffice for now.  And if it triggered any questions, let me know.  I’ll be happy to answer as best I can.

When I next write, it will be to explain a little about where I’ve been for the last three months.

As always, your questions or comments will be appreciated.  Please comment below or email me.  And thanks for reading. - Dave Alden (

1 comment:

  1. The road diet actually makes more sense on PB south than through town. I am skeptical of your traffic capacity and congestion impact numbers though. They may be correct on a daily average basis, but visit PB North between Payran and D any afternoon, and you are likely to find long backups extending all the way from Washington to D or a block or so south of D. SB traffic turning left at D also blocks NB traffic at D (because of backups at the bridge and/or Lakeville). Southbound traffic on PB North often backs up from Washington almost to Lakeville. I have found it is often faster to just bail out before D and go up to Kentucky and cross Washington there.. So the argument about no impact on capacity is suspect, given that there is lots of congestion, and a lot of the excess is just spilling over into alternates, putting more traffic into areas where we didn't really want it. I'd like to see a full traffic study (or a simulation) that looks at the impact on all of the streets. I think a key issue with the Diet is that it eliminates any excess capacity for the system, so under typical average conditions there is no impact, but when things get impacted they get heavily impacted because there is effectively zero reserve. It may be that the benefits outweigh the costs, but let's be fair in assessing the costs.. On Sunday morning there are no costs, but any observer can see that from about 4 PM to 6 PM mid week going through town is hell, and it wasn't as bad before the Road Diet.