I double-dog dare you to ask transportation experts to explain induced demand
I’ve been hearing planners and engineers admit “we can’t build our way out of congestion” since the 1990s when I began my career. You'd think they'd take their own advice.
Here’s how to explain car-oriented transportation planning:
“Welcome to the restaurant. Let me tell you about our menu. Pizza is all-you-can-eat, and it’s free. Everything else costs $50 each, and takes 8 hours to prepare. So, what can I get you?”
The experts don’t want you asking questions about the assumptions for road widening projects.
Of course they don’t—it undermines the vast majority of major infrastructure projects. Bring up induced demand with a group of consultants who need to win that big road widening contract, and see how quickly the subject changes.
How do modernist transportation planners recommend handling congestion? By recommending new vehicle lanes.
What happens when you build new vehicle lanes to handle traffic congestion? The vehicle lanes fill up with more traffic congestion.
As they themselves have said for decades, you cannot build your way out of congestion. But every week you can do a quick internet search to see a bunch of new attempts.
Transportation professionals have understood the induced demand phenomenon for decades. Consider the hypothetical (or is it?) Route 60.
Route 60 has two lanes in each direction with turn lanes at each signalized intersection. Most of the real estate fronting the corridor is retail or office, but thousands of single-family homes, townhomes, and apartments are just behind the other land uses. As you might expect, people choose to frequent the shops closest to home.
The department of transportation adds one more lane in each direction. After construction, people choose to visit more retail centers further from home because there’s suddenly more space on the corridor. It gets to the point where enough people have made the same choices that car traffic on the corridor is back to its pre-construction levels.
In response, the department of transportation builds one more lane in each direction. Now with four lanes in each direction, the corridor is wider than the nearby interstate. And once again, people who were avoiding the traffic jams on Route 60 now choose to get back on the road and drive further. Enough people make the same choice to drive further from home and the car traffic is back to pre-construction levels.
The might-be-fictional Route 60 is the same never-ending story of induced demand in communities across the country. Road expansions only temporarily reduce traffic congestion, but professionals only temporarily remember expansions don’t work.
Embrace Congestion
Signs of Human Activity
Congestion on local streets isn’t a blight that has to be improved. Congestion indicates vibrancy. As with so many infrastructure topics, the misunderstanding of congestion begins with the word itself.
modern congestion / noun, the state of traffic being blocked up like mucus
future congestion / noun, the state of human-paced movement indicative of a strong local economy
Some agencies have already begun to downplay the level of service mindset. Congestion is still measured by modernist methods (i.e. level of service), but it’s becoming a data set rather than a condemnation on transportation infrastructure. Consider how closely people walk past each other in a plaza, public park, or a downtown sidewalk. There’s no comparison between the tolerated levels of car congestion and people congestion.
Transportation planners will continue shifting to a more traditional philosophy: common sense. Future generations will have the luxury of clear hindsight when they lament the pain inflicted by modernist infrastructure expansion. They’ll clearly see the induced demand cycle.
Fiscal Responsibility
It’s no secret that public agencies are strapped for cash. And it’s no secret that public agencies continue to spend depleted accounts on new road construction projects. Meanwhile, the average citizen continues to point out problems with existing infrastructure: potholes, withering landscaping, crumbling sidewalks, and poor street lighting. The internet enables people to share observations, explore solutions from around the world, and unite around common causes (e.g. fiscal responsibility).
Taxpayers are losing tolerance for the modernist rejection of common sense. Their financial contributions deserve good stewardship. Don’t plan on building something that can’t be maintained.
Future transportation planning will be in sync with economic feasibility studies. Economists who track land value, small business trends, and the general preferences of millennials (nearly half the workforce in 2020) will be natural allies in the return to compact development. This type of development is commonly referred to as new urbanism, smart growth, or traditional neighborhood design.
Regardless of the term used, the principle is building and maintaining a transportation system that promotes the health of communities. When it comes to fiscal health, congestion is good for business
Plan the Future You Want
Make Deliberate Choices
It’s important to consider the relationship of activity between the curbs and outside the curbs. In other words, truly link land use and transportation.
Plan the future you want. Design that future for the fundamental modes of transportation—walking and bicycling. Your professional reward is observing people enjoying the community.
This type of transportation network planning will be a collaboration with land use planning, re-zoning cases, redevelopment proposals, and other place-oriented projects. Plan great places that people want to flock to, and they won’t have the urge to drive long distances to scattered, bland, unremarkable destinations.
Future transportation planners will resist the urge to follow the whims of forecasting models that always insist more lane miles should be constructed. Instead, planners will partner with community stakeholders to develop systems that provide mobility and access for people of all ages and physical abilities. This will inevitably lead to slower vehicular traffic, higher volumes of pedestrians and bicyclists, and stronger local economies. Planners will deliberately choose congestion over vacancy.
Watch Bike Lanes Fill Up
People rush to slow-moving traffic. The most coveted travel destinations around the world are places where walking and bicycling are convenient forms of transportation.
Planners are already taking advantage of the induced demand principle by creating bicycle networks that will fill up with new traffic. Slow rollers are the people pouring money into the local economy, not the motorists on the highway bypass. Future generations of planners will continue this trend, building on the success of early 21st century success stories in metropolitan areas around the world.
Modernism resists bicycle infrastructure, but common sense is breaking through the resistance. Robust bicycle infrastructure gives people the freedom to make short trips without having to rely on a motor vehicle. When people are able to make short trips on a bicycle, they can spend money locally rather than adding to the tax base of adjacent jurisdictions. And of course, bicycle infrastructure yields an extraordinary return on investment when compared to car-oriented infrastructure.
There’s one last argument that modern planners cling to...
“Not here. We aren’t Copenhagen.”
The Copenhagen complaint is one of my favorite talking points. It’s a case study that cities aren’t inherently bike-friendly. Culture plays a tremendous role in the planning and construction of transportation systems. When Danish streets were convenient for high-speed vehicular traffic and long commutes, that’s exactly how people behaved. Following a fundamental shift in design philosophy, bicycling was made convenient and Danes naturally opted for the easier travel mode.
America’s rural villages, sprawling suburbs, and big cities have so much potential. We’ll meet that potential as future generations lead the culture shift by using the induced demand principle for the greater good.