|Shifting even a small percentage of delivery truck traffic from business hours to off-hours, between 7 p.m. and 6 a.m., should help noticeably alleviate downtown New York’s infamous congestion and boost its economic performance, Holguín-Veras said. Keeping traffic moving in Manhattan will result in a greater influx of shoppers and tourists to downtown
locations as well as reduced automotive emissions and more breathable air.
Keeping traffic flowing at a steady beat in a safe manner is also a priority for Wallace, the Yamada Corporation Professor at Rensselaer and a member of the Department of Decision Sciences and Engineering Systems.
“It’s clear that safety and efficiency go hand-in-hand,” Wallace said. “We want to keep drivers moving at a constant speed. Acceleration and deceleration are where you use the most energy, and where you’re the least efficient. Accidents, which are already horrible for the people involved, also affect the rest of us by causing congestion, making us late, and ultimately wasting a lot of energy.”
Wallace is working on both theoretical models and applied devices for supplying drivers with reliable, real-time, in-car traffic updates. The devices use GPS technology and complex analytics to identify where traffic is backed up, alert drivers well before they reach the congested area, and then seamlessly direct drivers toward the most appropriate and efficient alternative route. Wallace tested a prototype of such a system, which included several solar-powered sensors on the site of the road to collect data, in New York’s Capital Region as well as outside Syracuse during the 2007 and 2008 New York State Fair. The study was funded by a $3.9 million grant from the Federal Highway Administration.
In addition to day-to-day rush hour traffic, Wallace said the in-car devices will also be particularly useful for decreasing congestion and providing travel time estimates in construction zones, at special events, and during emergency evacuations.
“With a little political will, and the appropriate funding, you could start rolling out this technology right away, and see quick, real results in alleviating congestion around the country,” Wallace said. “But it’s tough. New transportation technology, everything from cars to manufacturing equipment, is usually pushed through the private sector, whereas transportation systems and transit are the province of the public sector. It’s surprisingly difficult to marry the two.”
Wallace agreed with Holguín-Veras that making transportation greener and more sustainable is a critical yet severely difficult endeavor, which needs to be approached from a systems engineering perspective. He cited ethanol, a fuel additive derived from corn, as an example of how unforeseen consequences can arise when not looking at the big picture when rolling out new technology and policy. Federal regulations in recent years called for an increase in the production of ethanol, which in turn provoked a spike in the price of corn and corn byproducts that reverberated through the economy.
“The ethanol situation was a huge misstep, which someone did not think through all of the way,” he said. “Hopefully it taught us something. There are a lot of great ideas out there right now, like biomass and using algae as a power source, but we need to consider all of the different ecological and biological systems that will be affected by the mass planting or harvesting of biofuels. Plus we need to think about the energy it takes to do it, to make sure we’re still realizing a net energy savings and net greenhouse gas reductions.”
At the end of the day, Wallace and Holguín-Veras said that land use the speed, method, and patterns of how we grow our towns and cities is the central battleground for sustainability on a national level. Population density affords important critical mass that coaxes higher efficiencies from train travel and public transportation, but this will never be realized as long as municipalities have economic incentives to keep growing.
“Growing your town means getting a higher tax base, but it also leads to a host of other issues like congestion, longer travel times, and inefficiency,” Holguín-Veras said. “Without changing the land-use paradigm, it will be near impossible to slow suburban sprawl. We need to create new ways of incentivizing smart and sustainable growth, rather than just growth.”
Rensselaer Polytechnic Institute
“Switching Gears to Greener Transportation”
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