LosAngeles,California,forinstance,hasnosubwaysystemandthebusesareslow.Instead,mostcommutersdrivemanymilesfromtheirhomestowork.Manyofthesedriversspendseveralhourseachdayonbusyfreeways.NewYork,bycontrast,hasamasstransitsystem-buses,commutertrains,andsubways.Becausethepublictransportationiscrowdedanddirty,however,manypeopledriveprivatecars,andthetrafficjamsareworsethaninLosAngeles.
Ontheotherhand,somecitieshaveclean,fast,andpleasantpublictransportationsystems.InParis,France,andToronto,Canada,forexample,anyonecanusemasstransittomovequicklyfromonepartofthecitytoanother.
Thedisadvantagesofanymoderncityarenotuniquetothatcity-thatis,citiesallovertheworldhavetosolvetheproblemsoftrafficjams,crime,housing,energy,drinkingwater,andovercrowding.Yetmanycitieshavefoundanswerstooneormoreofthesedifficulties.SomeEuropeancities,suchasStockholm,Sweden,orLondon,England,haveplannedcommunitiesthatprovidepeoplewithapartments,jobs,shoppingcenters,greenspace,entertainment,andtransportation.ManyU.S.citiesarerebuildingtheirdowntownareas.Urbanplannerscanlearnfromoneanother.Theycantrysolutionsthathavebeensuccessfulinotherpartsoftheworld.