How Congestion Pricing and Traffic Jams Help the Environment

When us lay­men think of ways to solve traffic con­ges­tion we typ­ic­ally think of two ways: con­ges­tion pri­cing to force those who are most price sens­it­ive off the roads and on to pub­lic trans­port (which should be improved using the funds gained through said pri­cing), and adding capa­city to the roads. But do these solu­tions really help: do con­ges­tion charges and addi­tion­al capa­city really affect over­all driv­ing habits and are they bene­fi­cial for the envir­on­ment (do they increase pub­lic trans­port use)?

Traffic jams can actu­ally be envir­on­ment­ally bene­fi­cial if they turn sub­ways, buses, car pools, bicycles and walk­ing into more-attract­ive options. […] The tra­di­tion­al solu­tion to traffic con­ges­tion is to cre­ate addi­tion­al road capa­city. But pro­jects like those almost always end up mak­ing the ori­gin­al prob­lem worse because they gen­er­ate what trans­port­a­tion plan­ners call “induced traffic”: every mile of new, open road­way encour­ages exist­ing users to make more car trips, lures drivers away from oth­er routes and tempts trans­it riders to return to their auto­mo­biles, with the even­tu­al res­ult that the new roads become at least as clogged as the old roads. […]

In 1999, the Aus­trali­an research­ers Peter New­man and Jeff Ken­worthy con­cluded that “there is no guar­an­tee that con­ges­tion pri­cing will sim­ul­tan­eously improve con­ges­tion and sus­tain­ab­il­ity,” and men­tioned sev­er­al ways in which con­ges­tion pri­cing can defy the expect­a­tions of its sup­port­ers, among them by caus­ing motor­ists to “drive exactly as they always have if the con­ges­tion charge is covered by their firms (e.g., a major­ity of London’s peak-hour com­muters have com­pany cars and perks).”

Some have inter­preted Dav­id Owen’s column to be anti-con­ges­tion char­ging: I don’t believe he sug­gests this, primar­ily because of his final para­graph, describ­ing what he believes is the most effect­ive con­ges­tion man­age­ment pro­gram:

A truly effect­ive traffic pro­gram for any dense city would impose high fees for all auto­mobile access and pub­lic park­ing while also gradu­ally elim­in­at­ing auto­mobile lanes (thereby redu­cing total car traffic volume without elim­in­at­ing the envir­on­ment­ally bene­fi­cial bur­den of driver frus­tra­tion and inef­fi­ciency) and increas­ing the capa­city and effi­ciency of pub­lic trans­it.

It isn’t the solu­tion; it’s part of the solu­tion.