Capitol Hill Traffic Calming – Project Update (October 10, 2023)

Project Update (October 10, 2023)

Click here to read the report in it’s entirety

Traffic calming has arrived! The project team has made substantial progress implementing the Capitol Hill Traffic Calming Plan since construction began in August. Most of the speed humps are complete, and we are continuing to add signs and pavement markings to ensure visibility. Thank you for your patience with the construction, detours, and parking inconveniences.

Sticking to the plan

The project team delivered 58 speed humps, closely following the plan developed with the Capitol Hill Neighborhood Council. In a few instances, field adjustments were necessary – locating the speed humps is like threading the needle of existing constraints. Key considerations include:

  • Spacing to adjacent intersections, with preference for mid-block locations
  • Avoiding driveways
  • Avoiding utilities such as water laterals, sewer manhole covers, fire hydrants, Google fiber, etc.
  • Locating on parcel boundaries where possible
  • Locating near overhead street lights where possible to improve nighttime visibility
  • Minimizing need to trim existing trees for sign visibility

Invariably we find it necessary to make adjustments, however in general we stayed close to the plan.

Were there speed humps in the plan that were not built?

There are a few speed hump locations that we did not include in this construction package because the streets are concrete (segments of 300 N and 500 N). For various reasons, it’s better to put concrete speed humps on concrete roads. When preparing the contractor bid package, we try to avoid lumping tasks together that require very different equipment or skills. This construction package was designed for a particular construction method to build asphalt speed humps on asphalt streets. We are planning to return next year to backfill the remaining planned speed humps that require concrete.

What’s happening on East Capitol Boulevard?

After installation of the first three speed humps on lower East Capitol Blvd, the project team received numerous emails and phone calls from residents expressing concern. The primary issue was the shape/size and corresponding design speed of the humps. In the planning process the project team agreed to use a design with a higher design speed to fit the context of East Capitol Blvd, aiming for a 25 MPH average speed. To find the right balance, the project team installed a modified speed hump design for the three speed humps on the north (upper) segment of East Capitol Blvd. The modified design is an inch shorter than the three originally installed on the lower segment (2.5” vs 3.5” height). We then conducted field tests with the SLC Fire Department to evaluate emergency response impacts and followed up with a survey for residents to provide feedback.

155 people responded to the survey, which asked the following questions:

  • In your experience, at what speed to you feel comfortable driving over the 3.5” speed humps on the lower section of ECB?
  • At what speed do you feel comfortable driving over the shorter 2.5” speed humps on the upper section of ECB?
  • Do you support the modified, shorter 2.5″ speed hump design?
  • Do you use East Capitol Boulevard to access to your home?
  • Do you have additional comments or concerns?

The insights from the survey indicate that most respondents drive under 20 MPH over the larger 3.5″ speed humps, with a 90% majority going below 15 MPH. Over the smaller 2.5″ humps, 60% drive between 16 MPH and 25 MPH, with a slight 4% uptick in the 26+ MPH category.

Every survey respondent uses East Capitol Boulevard to access their home, and a significant 80% of the community approved of design change. Those who disapproved of the design change favored the taller, more aggressive speed humps, while many who approved of the design change did not want speed humps at all but indicated support for a less aggressive design.

Common concerns raised in the survey included difficulties in navigating speed humps in snowy conditions, emergency vehicle response times, and the safety of people riding bicycles, scooters, and skateboards.

Through this feedback, the project team decided to rebuild the three 3.5” speed humps on the lower segment of East Capitol Blvd using the 2.5” height, and include wheel cut outs designed specifically for fire trucks. This approach balances the project goals, considering the context and function of the street as a cul-de-sac collector to a large neighborhood with significant grade and intermittent snowfall.

For those concerned about the shift to less-aggressive speed humps and the resulting effectiveness in meeting project goals, keep in mind that it isn’t just one standalone speed hump that matters – it’s the systematic deployment and synergy from numerous locations along any given route that influence driver behavior. Even with a toned-down speed hump profile the system will still discourage excessive speeding and weekend exhibition racing, and increase safety for the neighborhood.

We do not work in an environment where we obtain universal consensus. The project team has made an exceptional effort to take feedback seriously and coordinate a rapid response (necessary because the asphalt construction season is nearly over due to cooler seasonal temperatures). We appreciate the engagement from so many residents on this project.

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