Hybrid Buses

    The town of Chapel Hill could significantly improve the fuel efficiency of their bus fleet and additionally reduce emissions of air pollutants, including carbon dioxide, if the town were to replace its current buses with new hybrid buses. Hybrid buses combine a diesel engine with an electric motor, similar to hybrid cars. Such buses are currently entering the bus fleet in Seattle. The Seattle transit authority expects a 40-60 percent reduction in carbon dioxide emissions and 20-30 less fuel consumption with the use of the new hybrid buses.

    In 2004, Seattle became the first city in North America to begin replacing its buses with hybrid diesel-electric buses.  Metro, the company installing the new buses, projects a 20-30 percent reduction in fuel consumption. Metro also anticipates less money spent on maintenance. Operating costs could be 30-50 percent lower than for the existing dual-mode Breda buses.  According to the Metro website, new hybrid buses will reduce emissions of the following pollutants by the following amounts:

• Particulate Matter (PM) by 90 percent over the cleanest diesel buses now in Metro’s fleet
• Carbon Monoxide (CO) by 90 percent over the cleanest diesel buses now in Metro’s fleet
• Hydrocarbons (HC) by 90 percent
• Carbon Dioxide (CO2) by 40-60 percent
• Nitrogen Oxide (NOx) by 50 percent

For more information about Seattle’s hybrid buses see: Seattle Transit Authority

Also see Hybrid Cars

Biodiesel

    Biodiesel is a clean burning alternative fuel made from animal fat waste, virgin plant oil, or cooking oil.  It is extremely practical because can be used in traditional compression-ignition (diesel) engines while still maintaining similar fuel consumption, horsepower, torque, and haulage rates to conventional diesel fuel. Biodiesel cuts emissions of harmful pollutants by the following amounts:

• CO2 – 78% reduction of emission in lifecycle (production, processing, transportation, and combustion) relative to lifecycle of pure fossil fuel
• Carbon Monoxide – 47% reduction
• Particulate Matter – 47% reduction
• Hydrocarbons (contribute to smog formation) – 67% reduction
• Sulfur Oxides and Sulfates (major components of acid rain) – approximately 100% reduction
• Polycyclic Aromatic Hydrocarbons (PAH) (identified as potential cancer causing compounds) – 75-85% reduction

    This revolutionary fuel is a great opportunity for Chapel Hill to reduce its carbon emissions, as well as total air pollution, while also supporting a new industry that does not rely on unpredictable, foreign, nonrenewable resources.

Source, see for more information:  www.biodiesel.org

For a study of Biodiesil at Dartmouth College see here.
 

Liquid Petroleum

    Liquefied petroleum gas (LPG) is a mixture of several gases, 90% of which is propane.  Unlike other fuels, propane or LPG is a natural byproduct of natural gas production and petroleum refinement.  This means LPG is produced every day for no extra cost, just waiting to be used by efficient consumers.  Actually, the US produces 90% of its own propane (one incentive considering America’s dependence on foreign oil).

    LPG or propane is the most widely used alternative fuel to date.  Traditionally, it has been used for everything from heating or cooling residences or business to fueling barbeque grills.  More recently, LPG has been used as fuel for cars, trucks, and buses.  In the US, propane fuels over 350,000 cars on the road today.

    LPG engines emit less Co2, carbon monoxide and other toxic emissions.  Some estimates say LPG vehicles reduce CO2 emission by 15% (about 12.7 lbs of CO2 per gallon compared to gasoline’s 19.6 lbs CO2/gal) and carbon monoxide by 60%.
Standard cars can be converted to run on propane for around $1000-2000 with conversion kits that can be bought from companies such as Ford, Chrysler, General Motors, or Caterpillar.  LPG vehicles maintain the same level of performance as standard vehicles, and their higher octane ratings actually result in improved engine performance.  Additionally, LPG engines have been known to last twice as long as standard engines.

    On average, propane costs 42% less than standard gas but is prone to price fluctuation.  However, these fluctuations can be avoided through long-term service contracts and bulk-fuel deliveries.

    Currently, LPG vehicles achieve slightly less miles per gallon than standard vehicles and are more expensive.  However, these costs are expected to decrease once demand increases for these models.  Another drawback is a safety trained person (usually and attendant at the station or dealership) must refuel the vehicle.  Although propane has the lowest flammability of all alternative fuels, it can be dangerous because it becomes a gas when leaked, easily ignited in a closed space.  However, if the leak is outdoors the gas is non-toxic and easily biodegradable, posing little harm.

Chapel Hill could clean-up its emissions by converting its transportation fleets to propane.  Texas provides a great model for the Town of Chapel Hill.  It has a law which mandates that all state agencies purchase alternative fuel vehicles and consequently has been using propane-powered vehicles since 1992.  There are over 4,400 clean running vehicles in their fleet, reducing carbon emissions with every mile.  Chapel Hill could make great process in its mission of a 60% carbon reduction by following this model.

Souce: EPA and Dartmouth research here
 

Increased Bus Ridership

    Increasing bus ridership can considerably reduce carbon dioxide emissions. Fortunately, Chapel Hill has already implemented a free bus system. The low number of bus riders therefore stems from other deterrents such as service quality and service frequency.  Chapel Hill should continue it progressive efforts in strengthening its bus system with the following suggestions to increase ridership:

• Campus Express – a bus arriving every 5 minutes
• Other routes – buses arrive every 7-10 minutes
• More shelters at bus stops to accommodate for inclement weather
• Increase parking costs
• Decrease parking spaces
• Intelligent Transportation Systems

Improved Bus Service

    Frequency of buses is the key to achieving high levels of ridership.  To compete with automobile transit, buses must just as convenient and predictable.  Buses that come every 20-30 minutes do not accommodate the busy schedules of businesspeople and students.  Their infrequency and unreliability discourage riders with any kind of time commitment. Also, added routes would make riding the bus even more opportune.  Increasing the frequency of buses, especially those that run to prime locations such as the UNC campus and the UNC hospitals, would likely increase ridership significantly. When buses come every 5 to 10 minutes, riders often do not need to consult their schedule or worry that the bus will make them late. Instead, if riding the bus were actually faster and more convenient than driving and parking, ridership would increase.  In addition, adding a shelter at every bus stop to accommodate for inclement weather will also increase the convenience of bus use.  However, before adding more buses or routes, Chapel Hill should first focus on increasing the ridership of the current lines through road “slimming,” publicity, parking policies, and Intelligent Transportation Systems.

Intelligent Transportation Systems (ITS)

    Transit Tracker is an information technology system that keeps track of real-time updated transit schedules and posts these actual times on electronic screens at transit stops.  Although it does not increase technical efficiency of a transit system, it does allow users more perfect information. For instance, if a bus is scheduled to arrive at 9:45 am but is not running on schedule, Transit Tracker will simply state that the bus will arrive to that stop in 10 minutes (or in whatever amount of time is true). The premise of such information technology is that greater information will make people more inclined to use the bus since they can predict each bus’s timing and therefore use their own time most efficiently. A multi-modal transit system such a Transit Tracker can even provide individuals with the best way to get where they are going, possibly taking into account minute-to-minute traffic reports and estimate travel times.  These features make the bus system just as predictable as automobile travel and even more convenient and appealing in some cases.  To increase ridership, Chapel Hill Transit should definitely consider installing an ITS system.

More information:
Transit Tracker system in Oregon
Government Report and Assessment of Transit Tracker in Oregon
General ITS information
Intelligent Transportation Society of America
 

    Estimating associated carbon reductions with each action is extremely difficult because there are many details that remain undefined- namely the extent of increase in the service and its realized change in individuals’ transit use and preferences.

Parking Policies

Limiting parking spaces or charging a greater amount for parking spots would encourage bus riding by making it more attractive and relatively more convenient and cost-effective. Additionally, for those who the bus system may not serve well, this policy could still carpooling over SOVs by providing preferred parking spaces for registered carpool vehicles.