The concept of induced demand is now widely recognized in transportation. But we often treat it as a technical modeling issue rather than a basic principle of how people respond to the world around them. Build for cars, and you’ll get more driving; build for transit or biking, and you’ll get more of those too. Shifting the conversation in that direction can improve near-term decisions and strengthen communication between transportation professionals and the public.
Demand Management
To reduce traffic, DOTs need both “carrots” and “sticks”
Nearly every state DOT is grappling with how to reduce traffic and carbon emissions—many states developed official , and congestion relief is often at the top of a DOT’s priority list. But a new study from Swedish researchers says that some of the most common ways to address these challenges—using only “carrots” rather than “sticks,” in the researchers’ words—may leave states struggling to achieve their goals.
Transit agencies are averting the fiscal cliff, but still need long-term funding solutions
Last month, SSTI staff joined the mayors of Milwaukee and two nearby communities for a meeting aimed at preventing a pending crisis for the local transit agency. Like many transit systems across the country, Milwaukee’s has exhausted its remaining federal COVID relief funds and was facing a 15% service cut and a 50% fare increase. Thanks to strong advocacy, the county has since proposed budget changes that would add $4.8 million to preserve service.
Caltrans review finds outdated and misunderstood models hinder project analysis
In California, where travel demand models often guide project-level decisions and analysis, a new report finds many are outdated, poorly documented, and ill-suited to the purposes agencies sometimes use them for. Transportation agencies rely on models to forecast traffic and guide billions of dollars in infrastructure investment. Without updates, these tools risk locking in old assumptions about growth and travel behavior rather than helping agencies plan for a more sustainable and efficient future.
Repairing highways is better for the economy than expanding them
The U.S. faces a $1 trillion backlog of roads and bridges needing repair, according to FHWA. Yet we still spend roughly $27 billion per year (25% of the total) expanding and building new highways. Mounting evidence shows that shifting those dollars toward maintenance and rehabilitation could yield greater benefits.
Despite efficiency gains, rising travel demand pushes emissions higher
Advances in technology have made transportation more energy efficient in recent decades, lowering emissions per mile and per unit of freight. But according to a new study, those efficiency gains haven’t been enough to offset the rise in emissions from new transportation demand. To hold transportation emissions steady going forward, the study says, global transportation demand must not continue rising, or we must make a more dramatic shift toward electrification than currently imagined.
More states are moving away from the 85th percentile rule to set speeds
States are increasingly moving past the outdated “85th percentile rule” for setting speed limits, weighing factors other than the observed traffic flow in those calculations. The AP recently highlighted Ohio among a wave of efforts to consider roadway context and the presence of walkers and bikers in allowing lower speeds to ensure safer roads. For states looking to follow suit, a newly released report from the Center for Pedestrian and Bicyclist Safety offers states a data-driven, objective framework to set speed limits based on roadway context, not just vehicle movement.
California will let agencies pay for housing to offset increased driving
A new California law gives transportation agencies the option to pay into an affordable housing fund to offset the increased travel demand associated with major road projects. The approach could achieve several goals at once: mitigating emissions from highway expansions, creating a new funding stream for affordable housing, and helping more people live in accessible neighborhoods, reducing their transportation costs.
The best transit plan is a strong land use plan
Increasing the number and variety of destinations around a transit station can encourage more people to use that station, but a new study shows more destinations concentrated around one station can also lift ridership across the entire network.
Congestion pricing could be the only path to managing gridlock
Transportation agencies in the U.S. spend billions of dollars each year expanding highways to ease gridlock. Yet commute times have increased 20% over the last 50 years and traffic congestion is still worsening, according to a several reports. New research confirms congestion pricing may be the best path toward any kind of relief. New York’s program, which launched in January amid plenty of controversy, looks like a promising example.