Chapter 11. The Molecular Unit
Once satisfied with our atomic units, we assemble atoms into molecules. These are corridors that prioritize bike transportation by linking multiple atomic units in sequence. For example, a series of diverters every 2-4 blocks, that connect to a sidewalk designated as a multi-use path, that, in turn, makes it possible to overcome a challenging boundary and connect to a regional trail.
The molecular unit of a complete bike network is also where we start to require the real outcome we seek: lots of people on bikes.
We can use temporary conditions to demonstrate molecular units. The precedent already exists: wildly popular pandemic-era programs such as Shared Streets in Denver and Open Streets in New York City, used little more than construction barricades to create people-first streets. In Denver, Shared Streets were supposed to last two months, but they were so popular that they lasted two years. When Denver finally removed the barricades and surveyed neighbors, they found that more than 90% of respondents wanted Shared Streets to be permanent.
This is all it took to create Denver’s Shared Streets program.
In Brooklyn, Berry Street, which started as an Open Street and became a permanent bikeway, is now a treasured community asset.
These programs provide the inspiration and precedent for our molecular units. When we ride our bikes down one of these corridors, we want to see people of all ages and abilities on their bikes as well. We want to see families, women, kids on bikes with 12-inch wheels. These people shouldn’t just be “bike people” – those who already ride and are stoked about the realization of their urbanist dreams. We need to be turning out new folks, people who live along these corridors and, once they see them, are going to support making them permanent.
That’s the whole point of Experiential Community Engagement: everyone experiences how their streets can improve.
Viva Streets was a short-lived ciclovía in Denver in which residents were treated to the experience of what the city could be like if Broadway, a major north-south arterial, were a bikeway.
As with the development of atomic units, our creation of molecular units should be iterative and scientific. Over a series of tests, we should home in on scalable, repeatable, templatized designs that maximize usage. Our observations should inform design iterations that optimize for:
Safety that’s in the Level of Traffic Stress 1-2 range and truly suitable for people of all ages and abilities.
Cost that’s 1-2 orders of magnitude less expensive than the conventional approach.
Time to implement that’s measured in days and weeks rather than months and years.
Enthusiasm and support from neighbors rather than conflict.
Soft materials like cones and construction signs can form the first few iterations. We should have strong measurement systems in place, particularly volunteers who sit at strategic locations and count the number of people on bikes and observe driver behavior, similar to the Portland Bicycle Counts. And as our designs get incrementally better, we should start to harden them with low-cost, permanent materials: signs, pre-formed concrete (rated for 30 years), paint, and thermoplastic.
A one-way diverter in Denver made from Do Not Enter and Except Bicycles signs prevents thru-traffic.
Our development of molecular units should also explore their effectiveness in different contexts: in gridded areas and those with winding streets, in wealthy and less affluent neighborhoods, in urban and suburban contexts.
As we do this, we need to refine our communications strategy through a series of tests. The variables are timing, the message itself, and how we reach people. Here’s an example of the full process:
Two days before we run the demonstration project, we flyer the neighborhood. The message is that we are working to reduce cut-through traffic and make the streets safer for neighbors and for walking and biking. We are clear about the date the project will go in and when we will remove it. We deliver the message in English and Spanish.
We install the molecular demonstration project and run it for a week.
We observe, count, and conduct intercept interviews.
During that time, 100% of people have the opportunity to interact with the project and provide feedback. (Contrast that with old school community meetings!)
We remove the project.
We flyer the neighborhood a second time and ask for feedback through a QR code.
We reflect on what worked well and what needs improvement.
We refine the process and repeat the experiment in the same location until we are satisfied with the level of biking, driver behavior, and neighbor enthusiasm.
Surveys, signs, and QR codes are among the communication techniques cities already deploy.
Throughout the creation of atomic and molecular units, a heavy reliance on precedent is essential: generally, we are creating nothing new. These processes and designs already exist in bits and pieces. We’re just assembling them in a more coherent fashion. We borrow the engineering from intentional diverters and de facto modal filters that already exist. And we borrow processes from people’s familiarity with temporary conditions in the roadway.
As Aristotle said, “Well stolen is half done.”