Not only do traffic engineers prioritize safety lower than residents, the designs that supposedly increase safety cause more death and destruction. Why? Because motorists behave differently than engineers expect.
Traffic engineers? safety improvements include paving wider lanes and shoulders, removing roadside trees, straightening tight curves, etc.? According to AASHTO standards, ?every effort should be made to use as high a design speed as practical to attain a desired degree of safety.?
Traffic engineers believe that designing for high speed will provide safety.
The crash data, however, show ?wider lanes and shoulders were associated with statistically significant increases in crash frequencies.?
Noland reports that traditional ?road ?safety improvements? actually lead to ? increases in total fatalities and injuries,? because ?this type of approach tends to ignore behavioural reactions to safety improvements?.
Dumbaugh reports that ?a behavior-based understanding of safety performance is supported by research and literature in the field of psychology, which has focused on the subject of traffic safety as a means for understanding how individuals adapt their behavior to perceived risks and hazards.?
We?ve seen that traffic engineers might improve safety by becoming better social scientists. Before following that, however, our next installment of Learning to Love Your Traffic Engineer will look at cost.
Going faster means getting there faster, right? Only if you?re on the mythical open road – in densely populated New Jersey, we have traffic.
Speed can work against getting there faster in traffic, since cars stay further apart – the best volume throughput is at 30-46mph. Improved signal coordination and speed harmonization allow people to get there faster even though they?re going slower, by delaying the onset of stop-and-go congestion.
Is it the end of ?build it and they will come?? If so, engineers will have one more reason to change their priorities. In our next installment of Learning to Love Your Traffic Engineer we?ll look at safety.
Comments Off on Learning to Love Your Traffic Engineer – Speed and Volume
It?s hard to learn to love our traffic engineers ? they don?t see the same world we do, and don?t want to talk about it. Why not? Have you been to a public meeting?
The public has issues – many residents have not learned to disengage knee-jerk thinking, do their homework or propose constructive suggestions. Some are hostile to any government action, including road projects.
We choose to live in West Windsor because of the promise of safety, good schools, open space and convenient train commuting. We love our cars, but don?t want traffic in our neighborhoods.
Charles Marohn, an engineer and planner, identifies the different values of residents and engineers. In order, residents prioritize safety, low cost, traffic volume and speed, while engineers prioritize speed, volume, safety and cost.
Value divergence shows in the effort to improve walking and biking along Cranbury Road. Despite WWBPA recommendations, residents? public comments and numerous yard signs asking motorists to Drive 25, traffic calming was rejected as a project goal.
We?re determined to learn to love our engineers, so in our next installment we?ll focus on the most divergent values ? speed and volume.
Comments Off on Learning to Love Your Traffic Engineer – What the Public Wants
We have to understand that traffic engineers love solving problems, just not social problems. They?ll design how to move cars through an intersection, but not how to preserve or create a downtown, increase property values or reduce pollution ? yet the intersection design can affect all these other goals, positively or negatively.
Although we?ve been building roads for millennia, we?re just realizing how motor vehicle traffic affects society. Using a computer analogy, traffic engineering is moving from the green screen to the graphical user interface ? people want a richer experience, including multiple ways to get where we?re going.
Traffic engineers must learn to see themselves as social scientists, concerned with how people in addition to motorists interact with the roadways ? residents, runners, dog-walkers, cyclists, etc.
People are puzzling ? we love our cars, but hate traffic ? how can engineers solve the dilemma? Find out in the next installment of Learning to Love Your Traffic Engineer ? What the Public Wants.
Monthly meetings are held at 7 p.m. on the second Thursday of the month via Zoom. We will eventually resume meeting in the West Windsor Municipal Building. Email us at [email protected] if you would like the Zoom code.
Find us at the West Windsor Farmers Market (Vaughn Drive parking lot) from 9 a.m. to 1 p.m. every other Saturday from May through Halloween.
