Street Design Matters

October 24, 2017 by Dan Hennessey

Take a look at the pictures below and try to determine for whom this street is designed:

I came upon this street while walking trying to connect through a neighborhood last weekend and I immediately thought to myself, who does this design work for? The 44-foot cross-section of pavement provides issues for users of all modes. An example of the contradictions:

  • There are striped bicycle lanes in both directions, but parked vehicles are scattered on both sides of the street for the entire 2,000-foot block. I had to confirm that they were in fact bicycle lanes and not striped parking areas; there are bicycle lane signs at the beginning and end of the block, but no bicycle symbols on the pavement. There are also no signs indicating that parking is prohibited on this block.
  • The remaining 32 feet are dedicated to two vehicle travel lanes. These two travel lanes have a posted speed limit of 30 miles per hour with five sets of speed humps along the block. Is this street intended for a high capacity (as indicated by the lane widths) or low speeds (as indicated by the speed humps)?
  • A four- to five-foot sidewalk on the south side of the street crosses 28 driveways (one per 70 feet), many with significant cross slopes.

You might also notice from the photo that there is significant grade on the roadway, which has an impact on the ability to provide bicycle facilities in both directions.

The City of Austin recently released the Austin Street Design Guide, which provides example street-sections for many different roadway classifications.  It is planned to be incorporated into a revised Transportation Criteria Manual.  The existing dimensions limit what can be accomplished for the competing interests mentioned above, but the following could be options with only striping changes,  without moving either curb:

This option would maintain the bicycle lane on the south side of the street (and remove parallel parking), while providing a parking-protected bicycle lane in the uphill direction. It might be preferred to keep the bicycle lane along the curb given the number of driveways along this block as well.

However, because this is a residential street, it might be more acceptable to the residents of the street to remove the downhill bicycle lane and provide parking on both sides, while providing a better bicycle facility in the uphill direction and more appropriate width for vehicle lanes. Emergency services in Austin would also probably appreciate the wide unobstructed width of this choice:

Both of these alternatives were thought of quickly, without detailed analysis, public input, or understanding of additional constraints. But streets comprise a significant amount of public space in cities, and too often they fail to serve the users they intend to serve. Drivers, cyclists, pedestrians, and other roadway users will use roadways how they are designed; it is all the more important that roadway design is done intentionally and deliberately.

We encourage you to contact us about your next traffic or transportation engineering project to see how we can help you to make it a great success.

Written by Dan Hennessey

Dan Hennessey

Dan Hennessey, P.E., PTOE is our Public Infrastructure Services Market Director. Dan holds a Master’s Degree in Civil Engineering (Transportation) from the University of California, Berkeley and a Bachelor of Science in Civil Engineering from The Ohio State University. Dan is responsible for managing our Raving Fans and prospective clients, overseeing the performance of our public infrastructure engineering design staff, steering our marketing strategy, and spearheading our community outreach and volunteer efforts. Dan’s professional experience and expertise focuses on Traffic Impact Analysis (TIA) studies, highway, freeway and arterial operations analysis, signal coordination and synchronization, traffic signal design, travel demand forecasting, and pedestrian and bicycle facility design.