Welcome to our 12 Days of Mobility series, which celebrates the launch of our Transportation Cost-Savings Calculator, a tool that measures the return of investment from transportation demand management (TDM) programs. Click the image to see the entire series. 

Everyone benefits when single occupancy vehicle trips are reduced, including drivers who face less congestion and taxpayers who don’t have to pay for endless road widening and excessive maintenance.

The people who benefit the most, however, are those with low incomes. In a time when global income inequality is at its highest in decades, this is especially important. Transportation demand management (TDM) can help make transportation more equitable by reducing its cost in health, happiness, and money to lower-income households.

Using TDM to provide more equitable mobility is an important tool to compensate for income disparity and move toward a happier, healthier society. Here are six key ways that the benefits measured by Mobility Lab’s Return on Investment (ROI) calculator help people with low incomes the most.

Air pollution

Asthma is on the rise in the United States, afflicting 20 million adults and 6 million children and teenagers.  The disease particularly strikes low-income and minority neighborhoods, which historically have been fractured by highways.  Other respiratory problems, along with heart attacks, strokes, and even childhood leukemia, are also chronic in neighborhoods near major roads.  The evidence is strong that tailpipe emissions exacerbate these problems.  Getting more people onto buses, trains, vans, and bicycles—as well as walking and telecommuting—thus benefits low-income neighborhoods disproportionately.

Climate change

Transportation is the leading cause of greenhouse gas emissions.  This summer’s confluence of heat waves and wildfires, as well as other “unnatural” events such as sudden and incessant rains, are just a small taste of what’s to come if we don’t change drastically. Yet it is low-income people—who contribute the least to climate change—who will suffer the most and first.

Hurricane Katrina is just one example of how wealthy people have the means to flee natural disasters worsened by climate change, while low-income people often cannot. The affluent are also more able to bounce back after natural disasters.  And, of course, lower-income households are less likely to have air conditioning and amenities that allow them to ride out heat waves in relative comfort.

Globally, the least financially stable countries are most vulnerable to climate change and its impacts, from flooding to food shortages to forced migration to new disease vectors that may accompany it.

Fuel 

While the average driver saves gas money when traffic flows freely, access to mobility without a car saves even more. A new car costs about $8,500 a year to own and operate, well over half of the $13,000 income by an individual in the bottom quintile. By eliminating or reducing this fixed cost, providing quality transit options saves lower income households money, so they can afford rent, food and other necessities.

Congestion 

In urban areas, those with low incomes must often live far from work and depend on a car when transit is unavailable.  As high rent pushes more people further from their jobs, congestion increases. In Los Angeles (ranked to have the worst congestion in the world) commuters spend over 100 hours a year stuck in traffic. Buses that must stop regularly to pick up and drop off passengers are further slowed (unless given their own lanes).

A combination of transit and smart growth—that is, building housing near jobs, amenities, and transit—can greatly alleviate this.

Safety

Pedestrian deaths are rising throughout the United States and are highest in struggling states.  Those with low incomes are often forced to walk, and they must do so in difficult conditions, since low-income neighborhoods are less likely to have safe crossing areas and usable sidewalks.

The phenomenon is global: the least financially stable countries carry half the world’s traffic, but suffer 90 percent of traffic fatalities. Widespread, safe access to transit, along with walkable, bikeable conditions benefits everyone, but it benefits those with low incomes even more.

Noise pollution 

According to the World Health Organization, noise pollution increases risk of “heart disease as well as sleep disturbance, cognitive impairment among children, annoyance, stress-related mental health risks, and tinnitus.”  A 2017 study found that “neighborhoods with median annual incomes below $25,000 were nearly two decibels louder than neighborhoods with incomes above $100,000 per year.” This disparity may be because low-income residents also have less political clout to demand sound barriers and less ability to pay for noise reduction where they do live. Homes that low-income households can afford are more likely to be near noisy roads.

Photo by Sam Kittner for Mobility Lab.