Friday, March 12, 2021

Latest Dangerous by Design Report is Good Context on 17th and 45th Street Speeds

The newest edition of Dangerous by Design on walking safety and the dangerous autoism in our road design doctrine is out, and its news is not good.

The number of people struck and killed each year has grown by 45 percent between 2010 and 2019, and 2018 and 2019 saw the highest numbers of pedestrian deaths since 1990.

We don't yet prioritize walking enough

Locally, Oregon and Salem do better with sidewalks and bike lanes. The report ranks Oregon in the middle of the states. We mostly avoid the worst practices illustrated in the report, large, zoomy stroads missing sidewalks and crosswalks. For years our design standards have met a minimum for people walking. Still, we have annexed streets built to unincorporated county standards that lack sidewalks and bike lanes. And even with the sidewalks and bike lanes, they are generally built to legacy standards from the 1970s and 80s, are often posted for speeds inappropriate for an urban context, and still do not do enough to protect vulnerable users of the road.

Crashes on 17th and elsewhere, injury and fatal
In cars = grey, on bikes = purple, on foot = blue
(SKATS, yellow added)

Killed in 2021

Killed in 2020

The recent discussion about speed zones on 17th and 45th Streets shows much of the problem.

Take 17th Street.

17th Street was one of the first, maybe the very first, 4/3 safety conversion in Salem a generation ago. We still struggle to implement these conversions, as the State Street "hybrid" plan attests. 

But that approach is old. With our need to reduce driving of all kinds for our climate goals, and with too much death from our autoism, it is time to leapfrog this approach and take our street design and traffic calming to the next level. 

Why leapfrog? By itself, the 4/3 conversion is not enough.

17th Street is signed partly for 25 and partly for 30mph. ODOT conducted a speed study there and found that the 85th percentile speed on a road was 36mph. 

Even with medians and enhanced crosswalks at Mill, Chemeketa, and Nebraska, people find it comfortable and banal to drive several miles an hour faster than the limit. 

The traditional approach has been to raise the speed limit to conform to this actual practice. This is, in fact, what ODOT recommended.

17th at Trade

Here's the speed chart for the section of 17th signed for 25mph, measured at Trade Street.

The traditional approach is to raise the limit

But if we were serious about safety, we would take a different approach. We could set the desired limit and posted speed as an 85th percentile speed (and some argue for a 95th percentile) and target, and retrofit the road to achieve this speed.

We could instead shift the curve and
reengineer the road for a slower speed

That this might seem radical is a cost of our autoism, making free-flow the desired outcome and congestion relief the dominant frame. That frame leads to might makes right: Constantly we read people saying that people just need to stay out of the way of drivers and their cars. People blame victims for not paying enough attention, for not deferring to cars sufficiently, and for not honoring the drivers of more powerful vehicles.

We have choose one of these frames
(front pages, June 2015 and June 2019)

There will likely be more to say when Council revisits the speed zone determination later this month. Problems on 17th and 45th are hardly isolated, and we should be thinking of system solutions, not merely spot solutions.

Signs are not enough

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