Into the Mind: ASU engineering professor Mikhail V. Chester explains how gas prices affect transportation planning.
What's behind the sudden drop in gasoline prices?
The low price of gasoline is largely the result of an excess supply of crude oil and low demand. The excess supply has occurred because, despite political turmoil, Libya has managed to more than quadruple production in the past few months. While the U.S. has experienced healthy economic growth in 2014, this is less so the case in Asia and Europe, which has translated to less driving and demand for fuels.
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How low could prices go?
Prices could continue to drop. However, supply and demand are out of equilibrium and we should expect the market to respond. Low prices are good for consumer's wallets but threaten the profits of oil producers. These producers will cut back production such that oil prices increase to where they're earning suitable revenue.
When gasoline prices rise, public transportation ridership increases. Does a drop in prices have the opposite effect?
Some portion of public transit travelers will shift to automobiles when gasoline prices are low, but this requires the household have a car that isn't being used. It's easier to reduce car use in favor of bus, rail, biking and walking when gasoline prices are high because these options do not require considerable out-of-pocket investments. However, many jobs and activities are only accessible by automobile, meaning shifts to transit are not always an option.
How does the volatility of gas prices affect transportation planning?
Households have time and cost budgets that they're willing to spend on transportation. Over a longer period, say six months to a year or more, higher prices tend to result in more fuel-economic vehicle purchases while lower prices can increase light duty truck and SUV sales. Changing fuel prices can even impact how far from a job households choose to live. Transportation agencies must predict changes in vehicle use and travel behavior to ensure mobility and air quality needs are met through appropriate infrastructure investment.
What defines sustainable transportation infrastructure?
Our transportation infrastructure has enabled remarkable economic growth over the past century, but there are increasing signs the system is deeply troubled. Our passenger infrastructure is dominated by roadways, many built in the mid-1900s. Rehabilitation costs exceed the budgets of transportation agencies.
Congestion is increasing in most major U.S. cities, auto-dominated travel creates air pollution that threatens public health and the climate, and tens of thousands die in car accidents each year. With an extensive automobile-oriented infrastructure, the Phoenix area is toward the top of city rankings of household spending on transportation.
A sustainable transportation infrastructure will give people choice in how they can travel, facilitate equitable access to jobs and activities, and not shift the impacts of travel (e.g., health impacts from exposure to tailpipe pollution) onto the population at large.
What should Phoenix's transportation look like in 20 years?
Because Phoenix is a new city our transportation infrastructure isn't complete, giving us flexibility in how we design urban form to improve mobility and livability. Over the coming decades Phoenix should aggressively pursue development within the urban core, where transport infrastructure already exists; bus, light rail, biking, and walking options exist; and households can be closer to jobs and activities.
Such development would decrease household costs, decrease public spending on infrastructure construction and maintenance, improve air quality, give us more options for protecting people from extreme heat, and provide our older population with greater quality of life.