The Role of Transportation in a Sustainable Future
The scientific community believes that greenhouse gases emissions, especially carbon dioxide, needs to be reduced by 50 to 80 percent by 2050 to stabilize the climate and avert economic and environmental cataclysm (IPCC, 2007). Transportation is responsible for about one-third of greenhouse gas emissions in the United States; passenger automobiles and light trucks alone contribute 21 percent. The built environment, transportation plus the building sector, accounts for more than half of the nation’s emissions. Increasing fuel efficiency and decreasing the carbon content of fuels can reduce vehicles’ greenhouse gas emissions, but the emissions reductions from technological fixes will be overtaken by the continuing growth in vehicle miles traveled (VMT). It’s clear that in order to reach our climate goals, we will have to reverse the upward trend in vehicle miles traveled.
A new culture of innovation is needed in transportation within our communities, as traditional solutions alone will not suffice. The suburban development patterns that have been aided by outdated policies must be changed to encourage better choices and more effective integration of land use, transit, cycling, and walking. Effective transit has the potential to serve our communities as we saw this summer as people found transit as an alternative to the high prices of gas. Yet public transit, carpooling, biking, and walking are unattractive in many cities because of the built environment we have created in the past forty years. In order to improve our communities and reduce carbon emissions, we have to find a way to improve public transit thereby changing the way our communities travel.
Is ITE and the Transit Community Prepared to Address this Issue?
The tools that ITE has been developing are starting to address these issues. The Context Sensitive Solutions Handbook is an example of a document that can be used to improve our communities given the realities of today’s challenges. The soon to be released Signal Timing Manual describes the importance of establishing policies prior to changing traffic signals and encourages the consideration of all modes. The use of these tools however lags because the dialogue within engineering circles remains largely focused on the old paradigm and the transportation policies of 1960s. We continue to consider moving cars as opposed to people in our communities, we favor single land uses as opposed to mixed ones, and we use tools that only consider automobiles as opposed to all users.
The Trip Generation and Parking Generation Manual are two documents that exacerbate the auto-dominated design of our communities and their use by many engineers fails to address the modes that are most important to our future. The Trip Generation Manual has a section on shared trips that considers multi-purpose trips within a single mixed-use development, but this is still very automobile focused and barely mentions transit. Further, concurrency requirements imposed in some jurisdictions limit development based on the projected capacity of available infrastructure, including roadway capacity. For example, developers might be required to pay for roadway expansion if a project is projected to increase traffic when road Level-of-Service degrades from C to D (Litman, 2005). This action discourages infill development and fosters dispersed, automobile-dependent sprawl. Revised concurrency requirements take into account the reduced per capita traffic generation, shorter trips and improved travel options in urban areas, and so allow more infill development (Wallace, January 2005).
Alternatives to concurrency models include use of a multimodal level of service concept or accepting congestion in exchange for transit improvements. If congestion increases, people change destinations, routes, travel time and modes to avoid delays. The competitiveness between travel alternatives has a significant effect on the use of various alternatives: For the alternatives that are inferior, travelers will choose the most attractive travel alternatives. The actual number of motorists who shift from driving to transit may be relatively small, just a few percent of total travelers on the corridor, but that is enough to reduce roadway congestion delays.
We must develop resources that address the new direction our communities will need to address the issue of climate change. Resources and handbooks are not enough to address the issue and may not be as important as steps that are necessary to result in a culture shift within the engineering community. This culture shift would be based on new values and a vision for the future. A vision which replaces the mindset that traffic delays must be mitigated, but rather seen as an opportunity to apply new techniques to improve transit, thereby helping transform travel behavior in the future.
Workshops to Cultivate Cooperation between Transit and Engineering
To meet these needs, the Institute of Transportation Engineers is excited about the opportunity to host five workshops to discuss model actions to shift our industry’s focus toward more sustainable transportation solutions. To attract discretionary riders (travelers who have the option of driving), public transit must be fast, comfortable, convenient and affordable. Engineers have an important role to helping transit agencies achieve this goal. A brief comparison of light rail transit and mixed flow bus service indicate the deep divide in investment and quality of transit. Light rail transit provides a travel time advantage that tends to attract discretionary riders. When transit is faster than driving, a portion of travelers shift mode until the congestion declines to the point that transit is no longer faster).
Transportation problems can be viewed as individual problems with technical solutions or opportunities to affect behavior. Traffic and parking congestion require building more roads and parking facilities, but these solutions improve the competitiveness of auto traffic as it compares to transit or non-motorized traffic options. To make the change our communities need, we need to focus on moving people and goods rather than vehicles. In dense cities, transit saves valuable space and energy compared to private automobiles and must be improved to maintain our mobility. Cities must also invest in bicycling and walking to further increase the opportunities for people to maintain a healthy lifestyle.
Transportation systems are a critical element of a strong economy, but can also contribute directly to building community and enhancing quality of life. As engineers, we have a responsibility to act as stewards of the natural environment, undertaking to help our communities make sustainable choices with regard to personal movement and consumption.
Other worthwhile facts to communicate the message:
According to the American Public Transportation Association, public transportation reduces carbon dioxide emissions by 6.9 million metrics tons annually, yet only 2 percent of the trips taken in the U.S are via this mode.
Eighty-two per cent of Manhattan residents travel to work by public transit, by bicycle, or on foot.Transit accounts for only 2 percent of passenger miles traveled in the U.S.
A study published in the City Journal stated that in almost every metropolitan area, carbon emissions are significantly lower for people who live in central cities than for people who live in suburbs (Glaeser, 2009, Winter). It goes on to suggest that land-use regulations bind most tightly in the places (existing cities) where environmental concerns should lead us to have the most growth.
An average U.S. urban dweller uses 24 times more energy annually for private transport as a Chinese urban resident, and around five times as much as a resident of a European city of equal economic prosperity. (Kenworthy, 2004)