Two Roads Diverged in a Yellow Wood, And I Took the One Designed Better
We unfortunately live much of our lives on roads. Although we spend around a third of our entire lives in a bed, a number of surveys and studies suggest we spend around an hour a day, or somewhere between 15 to 20 days per year in a vehicle, which equates to about 4 years of our lives in a car on average. With this large amount of time, it’s no wonder that advertising billboards, radio commercials, and signage is everywhere to convince us to buy more or patronize a particular store. We’re a captive audience by definition.
However, after so many repetitive commutes, seeing the same billboard, and completing the 500th mile on that extended family road trip, we invariable turn our minds to the road itself and we start thinking about how this all came to be - not in any cosmological way (although that does happen too!) - but literally, that is, how the road came to be - how it was designed and built.
Interestingly, many of us catch a glimpse of this process in pieces. While driving across the country on the interstate system, or even during inner-city driving, we will occasionally arrive at a road construction zone, especially during the summer, and feel temporarily inconvenienced that our progression was stymied. This glimpse before our eyes is just a snapshot of the entire road building process while this brief view can come from any stage in the overall process. Furthermore, we rarely see these road construction steps in order while we are all driving around for those four years of our lives, but eventually we get an idea of the full sequence of events and put the puzzle pieces together. There is the asphalt removal or basic clearing of dirt, rocks, debris as needed, the smoothing and sloping of the area which may include drainage slopes or piping, the sub base installation, which to me often looks like hard packed gravel, and then come the layers of asphalt, where there seems to be multiple layers (depending on the location) and which come in different densities, mixes, or properties, for purposes I can speculate but have never officially determined from books or a class. Also, near bridges and overpasses I’ve also noticed, and you have too, the rebar stage with welding and other reinforcement activities when the asphalt or cement is above ground.
Now, I’m probably missing some steps in the above list but then again I’ve only lived 2 of my 4 years in a car so far. I also don’t have a degree in civil engineering or have taken a class in road construction. I’m not an expert in this area and probably never will be. There are thousands of other details in that design process that go unnoticed from my position behind the wheel. Although I don’t know them in depth, I can still recognize those design details exist, appreciate those designers and engineers who have learned the trade, and marvel in this road creation process instead of expressing my impatience with the stop sign holder.
With summer vacation officially starting for many of us, I’ll share a couple of interesting and ingenious design features I’ve noticed over the years which hopefully can inspire you to think creatively in your own design activities to improve the experience for the customer. Indeed, I know that I am grateful for these developments and design innovation found on our country’s roads.
First of all, banked roads. I think I had already graduated from high school before I actually noticed this. It feels so natural to drive down the road with an angle or tilt downward into the center of curvature of a turn on a high-speed roadway that one can miss it. I’ve been on roller coasters and other amusement park rides without this track banking (by design) and the experience can be physically jarring. This roadway banking allows us to drive safer at a faster speed. Both of those are good design objectives and so finding a solution that improves both is a big win. We probably wouldn’t take road trips as often, it would take much longer to get anywhere, and it would be more painful without this banking.
Second, the markings and lines in the road. We don’t appreciate the contribution of lines to the design and, therefore, the overall experience of driving on roads much either. While living in a time where limitations, constraints, and boundaries are viewed as anti-democratic, the lines in the road can seem initially like unacceptable restrictions. But the first time I was driving 70 mph between two semi-tractor trailers, both which were a mere two feet away from my car, I was indeed grateful for these guiding lines. I was able to continue with confidence at full speed that all three of us would stay within our respective lanes (with some tolerance or margin of error built into the lane width as well). Yes, there’s an engineering discussion in all of this about directional vectors and relative velocities between our vehicles, but I’m grateful nonetheless. Some places in the world don’t have as many lines in their roads and although there are cultural protocols and an understanding between drivers that seemed to partially compensate, the efficiency is often lower.
Third, traffic circles. I love them. How many times have you been stuck at a red light by yourself as the only car for perhaps 30 to 60 seconds and felt your life was wasting away? All of that would be avoided with a traffic circle (among other things). In fact, chances are high you were strongly tempted to cut through that red light if no other person was around. A traffic circle would let you do that the moment the road was clear – without even a stop sign. Traffic circles have other really good benefits too. They are safer, (side impact/T-bone collisions are reduced, because vehicles have vectors that aren’t 90 degrees from each other), they can be cheaper (no traffic signals and electrical boxes required, so reduced life-cycle/maintenance cost), they are more aesthetically pleasing (monuments and art can be placed in the middle island), and they let you continue as soon as it is safe to do so. Downsides? Sure. Large traffic circles can take up a more space than a tight intersection, human drivers have to be a little more competent, and the vehicles have to slow down and make curving turns, which wouldn’t occur with a straight road. The simple red/green, stop/go traffic light is the best option for the worst of us drivers, but I still admire the communities that respect their citizens’ intelligence sufficiently to have multiple traffic circles near each other. Finally, checking phones at red lights becomes non-existent at traffic circles – there are no red lights, so everyone keeps their eyes on the road! Hopefully the trend for their return and increased popularity continues.
Fourth, green waves. These are when a set of traffic lights is timed with green lights such that you can drive through a whole bunch of intersections without stopping. This requires some good operations research, software engineering, logistics planning, and electric signal sequencing, but it makes the crossing of inner-city communities with many traffic signals a much better experience. I suppose this is a good counter response to the benefits of traffic circles. but green waves only benefit you when you have green lights. There are still times you have to wait at a red light when going the other way. Admittedly, the best systems have green waves in both directions, but those are more challenging computationally, especially when one wants their system to response to actual traffic congestion conditions.
Fifth, deceleration/acceleration lanes. These are simple concepts that are usually well implemented but they have a huge impact in reducing the disruption of traffic flow. Traffic congestion can be bad enough, but the increased variance of vehicles coming into a major road can exacerbate the problem. We’ve probably all been on a road when these deceleration/acceleration lanes were too short and someone, either the other driver or us, started panicking in some way. On the other hand, we don’t appreciate when the design of these lanes is adequate and we simply speed up and go on our merry way. That’s actually a sign of good design, that is, good design is often when we don’t really notice it – it feels natural and obvious. So, if you do notice it at some point, at minimum, appreciate the good design choices that went into that highway exchange.
Sixth, the diverging-diamond interchange. I came across this type of freeway interchange (officially a service interchange) for the first time in Georgia. It was, at first, odd to drive on the left side of the road for a short distance on the overpass, but it was exciting to see something new while driving for once. We all know the classic clover-leaf interchange and probably the stack interchange (even if we don’t know the name) so I was happy to see the adoption of a new innovation. I later investigated its benefits and was impressed. A diverging diamond can have higher throughput (a major evaluation metric used by traffic engineers) especially during low traffic times, be more safe especially with respect to turning left in front of traffic, and be less expensive.
Seventh, active and passive lights and reflectors for night driving. These are now found everywhere and they’ve done a lot to increase the safety of our road system. We take them for granted until they are not there or when we are lost and can’t see anything, such as in fog, and desire a point of reference while driving. These reflectors are found on road barriers, signs of all types (directional/informational/warnings), on other vehicles, and in the roads themselves such as in the line paint directly or on raised markers. These reflectors can guide, direct, suggest and many other verbs that help with driving during the night. Active lights usually perform the same functions but don’t rely upon the headlights of one’s own vehicle to be reflected. These are found in particularly dangerous corners and locations where the driver needs to see some flashing indicators but might not have the angle or geometry to reflect its headlight. On more than one dark, snowy night in Canada, I’ve been grateful for the flashing red octagon around a stop sign. That’s good design.
Why am I sharing this? Because everywhere you look, and also where you don’t look, there is good design. In my opinion, the above examples just scratch the surface of good design in our ground transportation system. There are many more I could discuss (e.g. Fresnel lens on traffic lights, ramp meters that control traffic entrance, rumble strips, etc.). I believe that becoming a good designer requires a lot of things, but at least two of them are noticing good design and thinking about how those good design decisions came about. Of course, we can learn from bad designs and failures too [LINKS HERE], but we all need a healthy dose of good ones. Fortuitously, the world’s roadways are replete with design learning opportunities. Use those four years of your life, learn something, and become a better designer. You’re stuck in traffic anyway.
