Innovative Transportation & Adaptability
Can drivers learn new things?
Background
I graduated with a Bachelor of Science in Urban, Rural, and Environmental Planning (after several changes in my major btw, but that’s another story).
After graduation, I was fortunate to find a job at a Metropolitan Planning Organization (MPO) called COMPASS. I graduated in 2008, during an economic downturn, so when I said I was fortunate, I was indeed. Also, MPOs are focused on regional transportation planning, so it was great to build upon what I learned in college from a regional perspective.
MPOs
MPOs are interesting organizations because the average citizen has probably never heard of them before…I didn’t know they existed until I became involved in urban planning.
MPOs are organizations mandated to exist by the US Federal government to facilitate regional transportation planning for urban areas with a population of 50,000 or more.1 They often adapt to the region and are sometimes organized as Councils of Governments and other association-type organization structures that are funded by both the Federal government and local/state entities. This is important because even though Federal regulations created their existence, and therefore are required to comply with associated regulations, they also adapt to meet the needs of their regional stakeholders.
I worked for the Community Planning of Southwest Idaho (COMPASS). It was a great place to work and I learned a ton through various projects, from my coworkers, and professionals representing city, county, and state entities, and my research interests as a regional planner.
Innovative Transportation Systems
One of the coolest things I learned early when I started at COMPASS was about innovative designs for streets and roads—focused specifically on intersections.
Why innovations at the intersection level?
Below is an excerpt from the Federal Highway Administration.
Intersecting roadways are necessary to connect people driving, walking and bicycling from one route to another. However, where roads intersect and paths cross, the resulting conflict points create circumstances where crashes can occur. In fact, each year roughly one–quarter of traffic fatalities and about one–half of all traffic injuries in the United States are attributed to intersections. That is why intersections are a national, state and local road safety priority, and a program focus area for FHWA.2
Transportation systems are….systems. They are highly connected and that connectivity creates multiple ways to get from point A to point B. However, that comes with a cost—multiple points of conflict and potential collisions. So how do traffic engineers and planners continually improve intersection efficiency and safety?
A key aspect of good intersection design is how to safely and efficiently handle traffic turning left. When you turn left, you cross oncoming traffic, which is intrinsically dangerous, versus turning right. It is not only dangerous for automobiles, but it is deadly for pedestrians and bicyclists because you may not easily see them cross the street given your focus on the oncoming traffic.
This post will not go into each option for safe intersection design but I will focus on the one that was most intriguing to me when I first learned about it. Later posts will expand other options.
The Continous Flow Intersection (CFI)
Continuous Flow Intersections (CFI), sometimes called Displaced Left Turns (XDL or DLT), are based on a relatively new design to address issues with left turns. They have been around since the late 1990s.
The below image is from VDOT (Virginia Department of Transportation) video about DLT/CFI designs.
The key factor is the left turn lane has a stop light well before the actual intersection, located in the below image with circles. They wait there until the road perpendicular to them starts to move through the intersection. When this happens they then cross the street safely cross the street into a holding bay. Once the signal changes to allow their direction of traffic to flow through, they then turn left, without crossing oncoming traffic. They still need to watch for pedestrians and bicyclists but given the reduced need to watch oncoming traffic, they are better able to watch for those alternative transportation modes.
Below is a different angle for the above intersection that shows the flow of traffic for those turning left, driving through the intersection, and turning right (this one shows a protected right turn lane as well.
It is much easier to see how it works with animation, per below video.
Can people learn?
I worked for COMPASS over 15 years ago and while working there the Idaho Transportation Department (ITD) was already planning to build a half-CFI at a busy intersection (half meaning the displaced left turn was only on one leg of the intersection, not both). It was located in Eagle, Idaho at the intersection of Highway 44 and Eagle Road.
When ITD started to get ready to build the design in 2021 (10 + years after I first learned ITD planned to build a CFI), they received a lot of negative feedback to the point they changed the design to a regular intersection at the cost of a safer and more efficient intersection.
This decision was very frustrating for me on many levels. One, it was planned for over 10 years and a lot of work went into the analysis and planning. I remember around 2008/2009 watching a computer simulation of CFIs that included simulated drivers who were confused. The CFI design is new and would initially be confusing but the majority of people who use it would easily get used to it. People who are not from the area would be able to follow the signs.
The biggest frustration for me was reading comments on social media and other places when people called the design “idiotic” and even bashed engineers as “stupid” for designing such a thing. I wanted to educate people but it wouldn’t have done any good so I didn’t.
In reality, it is not an idiotic design and the engineers who originally developed the concept were not stupid at all. They were brilliant!
Think of the challenge it solved. How do you make left turns safer when crossing oncoming traffic?
The answer.
By designing an intersection where they don’t cross oncoming traffic when turning left!
Even though the derogatory comments about the design and the people behind were uninformed and unfounded, they did provide one legitimate item of concern.
Some people would get confused.
That is true.
But should that limit progress such as this? Also, what does that say about our society and humanity in general, are we incapable of learning? CFI’s are not perfect, they do have some issues still, but they do represent the continuous improvement of our transportation system.
How can the Federal Highway Administration, state DOTs, and other entities ensure people know how to use these intersections beyond what they already have done? The video below was from the Idaho Transportation Department outlining how the CFI would work and there are many more out there from other sources.
Maybe these entities should require as a condition of renewal for license plates the completion of online training on how CFIs and other innovative designs work.
Ironically, as I get on my soapbox about not letting concerns about people’s ability to learn slow progress, I am reminded of when I first used a different type of innovative design for highway interchanges. I knew what it was but I still got confused and had to go through it twice to figure it out. :-) So I do understand the concern about driver confusion, but next time I come across that interchange, I will know how to use it.
The story behind that experience will be for another post.