When I became a “Traffic Analyst,” the title on my first business card coming out of graduate school, I thought I’d be spending the rest of my career developing trip generation tables, running level of service analyses, and making recommendations for green times, turn lane lengths, and yellow clearance intervals. We were using computers to do these calculations—so advanced! What needed to change in the field of traffic engineering?
Somewhere in the last three decades, traffic engineering has grown to encompass so much more than these metrics, which almost entirely involved how quickly you could move a car in the peak 15 minutes of the weekday. Today, a level of service analysis may include not just the experience for motor vehicle drivers but for pedestrians, bicyclists, and transit riders, as the Highway Capacity Manual multimodal level of service analysis methodologies were introduced in the 2010 edition.
Now there is also a level of service of safety, a concept introduced in the early 2000s. Where previously we would have looked at the history of accidents (we didn’t start using the term “crashes” until the late 1990s) at a location and reacted, we now can anticipate conditions that may be prone to crashes. Rather than looking at all crashes, we focus our efforts on eliminating life-changing crashes—those that involve serious injuries and fatalities. Speaking of safety, it is now at the forefront when we are designing transportation facilities—or at least it should be. It used to be that efficiency was goal number one, or even the only goal.
When I started my career, roundabouts were a newfangled design from Europe that very few American cities used, and I would guess were unpopular with most Americans. I was actually working in a city, Las Vegas, where modern roundabouts were being built routinely, but this was definitely on the leading edge. I’m not sure I had even driven through a roundabout prior to the ones I drove through there in a development called Summerlin. Today, nearly every trip I take in my car will involve a drive through a roundabout.
Traffic engineering technology has grown by leaps and bounds since I started my career. Vehicle detection loops were first replaced by video cameras, and now with radar or LiDAR (or even all of the above!) we can not only just detect the presence or absence of a vehicle, but estimate its trajectory as well. On the topic of technology, I recently started taking Waymo when it is an option. I video-recorded the first ride I took, and you can hear my audible gasp of delight in response to this new mode of transportation, something I never thought I’d experience in my lifetime.
Of course, some things about traffic engineering haven’t changed. Most of my family members, friends, and even total strangers consider themselves traffic engineers (due to their possession of a driver’s license). Most people will estimate their delay at a red light on the order of 10 times what it actually is, and residents will insist that unwarranted all-way stop signs will help the traffic situation in their neighborhood.
The past 30 years have brought transformative changes to traffic engineering, from groundbreaking technology to a growing emphasis on safety and alternative modes of transportation. Despite all of these changes, its core purpose—helping people get from here to there—remains as fulfilling to me as ever.