30th Street already has projects underway, but it's one of Boulder's arterial streets that will continue to see improvements as part of the city's Core Arterial Network (CAN). Credit: Harry Fuller

Traffic hums constantly through arterial roadways like Broadway and 28th Street in Boulder. As the name suggests, these streets act as vital arteries that move large numbers of people — in cars, on bikes and on their feet — throughout the city on a given day.

The large volume of traffic on arterial streets naturally leads to more conflict on the road, and thus a larger share of accidents. The city’s 2022 Safe Streets Report found 65% of severe crashes are occuring on these major thoroughfares. 

As a result, the City of Boulder announced earlier this month it would begin shifting its transportation safety focus away from local streets and toward the development and improvement of the city’s Core Arterial Network (CAN) through “a connected system of protected bike lanes, intersection enhancements, pedestrian facilities and transit upgrades that will help make it safer, more comfortable and more convenient for people to get where they need to go via Boulder’s main corridors.” 

Devin Joslin, principal traffic engineer for the City of Boulder, spoke to Boulder Reporting Lab about the Safe Streets data, and what this shift will mean for Boulderites looking for safety improvements to local streets.

This conversation has been edited for brevity and clarity.


What prompted the city’s shift in transportation safety efforts from local streets to the Core Arterial Network (CAN)?

The Safe Streets Report has the data from 2018 through 2020. As far as the the crash summary of what’s been happening in the city, you’ve probably seen the statistic that something like 65% of our severe crashes occur on our arterial streets — although our arterial streets make up, I think it’s 16 or 17% of centerline miles within our system. 

So, it is pretty clear from the data that the crashes where people are getting seriously injured, or sometimes killed, are most frequently occurring on the arterial streets. With CAN, it is an opportunity to see where other areas within the arterial network could potentially be improved over the next few years. 

What kind of accidents are making up most of those severe crashes on these roads?

In the Safe Streets report, we do a very comprehensive analysis to capture every single crash that occurs — whether it’s between a car and a car, a car and a person walking, or a car and a cyclist. Or, sometimes you do get crashes that involve maybe a bike against a person walking. All of that is accounted for within the data that was analyzed for the Safe Streets Report. 

Given the city’s priority shift from local to arterial streets, how are you approaching projects differently going forward?

I don’t know that our approach has necessarily changed. I think on the arterials, the projects may be a bit more complex, because there are more vehicles and higher transit levels and potentially just a higher volume of cyclists and pedestrians as well. 

But it’s not as if people don’t walk and bike and drive on local streets. So it is similar. But it is a little more detailed or advanced type of work that occurs to take all those things into consideration. Arterials also have higher speeds. So that’s a consideration as well, and ensuring that the balance between moving vehicles and moving transit is thoughtful and considered against the need to move pedestrians and cyclists along those corridors as well.

I do want to emphasize that it’s not as if we were turning a blind eye to safety before CAN. But now I think it is a more focused effort on some of these more major corridors, which may have a higher return on investment. With the funds you’re investing to make improvements, you’re going to hopefully receive a better return in terms of the crashes you’re reducing.

How will the city respond to traffic problems on local streets?

We are certainly going to remain responsive to community concerns, as far as things related to traffic control on local streets. Sometimes we’ll get requests for crossing treatments to be installed at a certain location, or we’ll hear from folks that there may be some parking challenges along streets. We sometimes hear concerns about the ability to see at an intersection — maybe there’s bushes or something that obstructs your view. And we’re certainly going to continue to respond to those, even if they’re on local streets. So that remains a focus of our day-to-day work. But the ability to deploy traffic-calming devices, I think that has been paused on our local streets.

Does that mean a pause on installing things like speed bumps, or are you talking about smaller projects with traffic paint or posts? 

I would say it is a full pause, both on things like speed humps and speed cushions and more permanent-type devices we’ve been installing historically as part of our Neighborhood Speed Management Program (NSMP). That also includes those you mentioned that were installed as part of our Vision Zero Innovation Program — some of the lower-cost projects that involve paint and plastic posts. But we are conducting a full evaluation this year of those Vision Zero projects that were lower-cost, just to understand their effectiveness and then look at that as a potential option for a tool we could deploy more extensively in the future.

With all that on pause, how will speed issues on local roads be dealt with?

We are intending to maintain our Photo Radar Van Program — that is a program our police department oversees, which is geared more toward the local streets. In fact, by law, it’s really not allowed to be deployed on our arterial streets. So I would say the photo radar van remains a viable option for folks. 

But again, resources are limited, and it may not be immediate, as far as requests go. It would get put in a listing of all the other requests, and then deployed as resources allow. So the radar van might get deployed for a day on a requested street, and it’s possible the person who requested may or may not see the van that day. So it may appear as though things are not occurring just because of the fact that it is a limited resource we try to deploy across the city.

I do believe we still have some mobile speed trailers that have radar signs that can display the speed at which people are driving back to them, and I think that is still something that remains an option to get out on the street. It doesn’t actually record the speeds, so it would be more about alerting drivers of the speed they’re traveling, with the hopes that if they see they are exceeding the speed limit, they’ll slow down.

So, there are still some options available. But it is a limited resource. So it may not be an immediate response to someone’s request, as far as feeling like it satisfies their need — and it would be balanced against other priorities of deploying that resource across the city. 

How much funding is actually being diverted from the neighborhood streets to these arterial streets? What kind of budget is the city working with for these projects?

The NSMP budget and the budget for implementing Neighborhood GreenStreets have been reallocated to help fund the CAN projects. [Editor’s note: The NSMP has had a 2022 annual budget of around $250,000 and the Neighborhood Green Streets had a budget of $75,000, according to the 2022 Approved Budget for the City of Boulder. The full CAN budget details have yet to be finalized.] But I would say funding is something we are still exploring in more detail. And I do think we’re anticipating there may be some gaps in terms of being able to fund these CAN projects, as outlined.

You may have seen during the [recent] Transportation Advisory Board meeting, there was a presentation as far as our plans for the Denver Regional Council of Governments (DRCOG) Transportation Improvement Program,  or TIP, grants. And we are intending to submit the Baseline Road corridor for a TIP consideration.

The challenge with the TIP grants is that they are a more regional funding pool and you compete against all the other cities within the Denver metro area. They have scoring criteria that’s pretty clearly outlined, but it is a competitive grant process. Projects are considered against the merits of other projects within the region. So Baseline and all the other projects the city submits for consideration will go through that competitive process for a final determination, as far as if it’s awarded the grant or not.

Is there any expectation for when the NSMP will go back to its normal operation? Or is this the end? 

We are actively assessing our workload and our funding to pivot and address the council’s desire for us to allocate more resources toward those arterial projects, understanding that it’s a trade-off of the NSMP pause. So, I think it’s an indefinite hold at this time. 

City staff will be updating the Transportation Advisory Board on the CAN during their April 11 meeting.

Harry Fuller

I’m an intern with the Boulder Reporting Lab, currently finishing my journalism degree at CU Boulder. I’ve written stories on various topics and currently work as a sports photographer for CU’s student paper, The Bold. I’m interested in what’s going on around Boulder and love nature and sports photography.