Environmental Problems, Their Causes, and Sustainability 1

T rade-OffsMass Transit RailT rade-OffsBusesAdvantagesDisadvantagesAdvantagesDisadvantagesMore energyefficient than carsProduces less airpollution than carsRequires lessland than roadsand parking areasfor carsCauses fewerinjuries anddeaths than carsReduces carcongestion in citiesExpensive to buildand maintainCost effective onlyalong a denselypopulated narrowcorridorCommits riders totransportationschedulesCan cause noiseand vibration fornearby residentsMore flexible thanrail systemCan be reroutedas neededCost less todevelop andmaintain thanheavy-rail systemCan greatlyreduce car useand pollutionCan lose moneybecause theyneed low faresto attract ridersOften get caughtin traffic unlessoperating inexpress lanesCommits riders totransportationschedulesNoisyFigure 25-12 Trade-offs: advantages and disadvantages ofmass transit rail systems in urban areas. Pick the single advantageand disadvantage that you think are the most important.Figure 25-13 Trade-offs: advantages and disadvantagesof bus systems in urban areas. Pick the single advantage anddisadvantage that you think are the most important.city is densely populated, making it ideal for a rapidrailsystem running through its corridor. Second, halfthe population can walk to a subway station in 5 minutes.Third, a car is an economic liability in thiscrowded city even for those who can afford one.Buses are the most widely used form of masstransit within urban areas, mainly because they havemore advantages than disadvantages (Figure 25-13).Curitiba, Brazil, has one of the world’s best bus systems(Figure 25-1).A rapid-rail system between urban areas is anotheroption. In western Europe and Japan, high-speed bullettrains travel between cities at up to 330 kilometers(200 miles) per hour. Figure 25-14 lists the major advantagesand disadvantages of such rapid rail systems.In 2004, Shanghai, China, began operating theworld’s first commercial high-speed magnetic levitationtrain between its airport and downtown. Thetrain, suspended in air slightly above the track andpropelled forward by strong repulsive and attractivemagnetic forces, travels much faster than bullettrains.In the United States, a high-speed bullet train networkcould replace airplanes, buses, and private carsfor most medium-distance travel between majorAmerican cities (Figure 25-15, p. 576). Critics say sucha system would cost too much in government subsidies.But this ignores the fact that motor vehicle trans-T rade-OffsRapid RailAdvantagesDisadvantagesCan reduce travel by caror planeIdeal for trips of 200–1,000kilometers (120–620 miles)Much more energy efficientper rider over the samedistance than a car or planeExpensive to run and maintainMust operate along heavilyused routes to be profitableCause noise and vibration fornearby residentsFigure 25-14 Trade-offs: advantagesand disadvantages of rapid-rail systemsbetween urban areas. Pick the singleadvantage and disadvantage that youthink are the most important.http://biology.brookscole.com/miller14575