Highway design could decrease death and injury risk, if “we” chose smarter designs

Is this highway interchange in the Dubai desert a waste of land, or a clue to better highway design that reduces the chance of death or injury?

I just saw this, and my first thought was “what a waste of land” and “why not just a normal intersection”?  Then pondering the traffic flows through this interchange, I realized that this sort of intersection would result in fewer traffic accidents.

A “T” style intersection, as is common in the U.S. for this scenario, has a certain risk of traffic accidents as vehicles attempt to enter the cross-road from the tail of the “T”.

Looking at this traffic circle, what I see is a lot less opportunity for competition between vehicles.  At a regular T intersection, the problem is traffic trying to go from one section to another have to stop and then negotiate entry into the other section, while getting back up to speed, resulting in the occasional accident.

With this sort of traffic circle it’s likely a vehicle coming to the intersection won’t even have to stop.  They’d just enter the circle, navigate around to the place where they want to exit, and then do so.  Further, for a couple of the use cases the bypass ramp roads let traffic completely avoid the circle.  It seems the chance for accident is much lower.

It’s educational to look at the context in which this intersection is located (Google Maps Link).

It’s clear that traffic circles are commonly used in that area.  But they’re not universal.  A few miles away is Dubai City, and the city streets are full of the common four-way stops.

One of the long-tail-pipe issues with the transportation is death and injury from traffic accidents.  Couldn’t the road system could be redesigned to give fewer opportunities for accident?

Ultimately the root cause of all traffic accidents is that someone wasn’t paying attention, leading to an unfortunate occurrence.  That’s why we call them accidents, because presumably none of us want to purposely cause collisions with other vehicles and the resulting pain and suffering.  (Yes, okay, there are occasional people who DO want to purposely cause collisions but I believe their number is very low)

Personal responsibility is therefore very important.  All of us drivers have to learn to pay attention, look around us, evaluate the rest of the traffic for risks, and take action to avoid danger.  Unfortunately most people are sleepwalking through driving.

At the same time what if some sorts of road infrastructure are simply riskier than other sorts?  The four-way intersection is a tricky thing, isn’t it?  If there are cars waiting at each entry into the four-way, which car goes first?  That negotiation sometimes results in accidents, as do the occasions when people fail to stop for the intersection.  The personal responsibility to drive well is one thing, but it’s quite another thing if highway design simply makes accidents more likely.

What if there were other ways to construct road interchanges to reduce the chance for accident?  This traffic circle is an example because it seems to chances for accident by the design of the interchange.

Over on GreenTransportation.info I’ve collected a few videos going over street design methodology in places like Amsterdam to make for better integration of bicycles, pedestrians and cars/trucks.

The common problem is the car drivers umbrage at the needs of bicyclists and pedestrians, ignoring the fact that most of us will take the role of bicyclist or pedestrian or car driver from time to time.  Somehow it’s an inconvenience to car drivers that road space is taken up by bicyclists, or that drivers have to wait at intersections for pedestrians to cross, and so forth.  Further, there are a significant number of accidents as we all fail to adequately negotiate the integration of all modes of traffic on the roads.

The videos above go over well thought-out intersection designs that give room for all three camps, while reducing the chance for negative interaction between them.  These are examples other cities could follow to redesign road systems for greater inherent safety.

About David Herron

David Herron is a writer and software engineer living in Silicon Valley. He primarily writes about electric vehicles, clean energy systems, climate change, peak oil and related issues. When not writing he indulges in software projects and is sometimes employed as a software engineer. David has written for sites like PlugInCars and TorqueNews, and worked for companies like Sun Microsystems and Yahoo.

About David Herron

David Herron is a writer and software engineer living in Silicon Valley. He primarily writes about electric vehicles, clean energy systems, climate change, peak oil and related issues. When not writing he indulges in software projects and is sometimes employed as a software engineer. David has written for sites like PlugInCars and TorqueNews, and worked for companies like Sun Microsystems and Yahoo.

Leave a Reply