Transport & mobility
Transit, road safety, cycling and congestion. Real interventions, each with its sources: what worked, what didn't, and why.
8 worked4 mixed2 didn't work
What worked
- WorkedTransport & mobility
Medellín's Metrocable
ChallengePoor hillside neighborhoods were cut off from the city and plagued by violence.
Cable cars connecting hillside neighborhoods to the city's metro system.
66%greater homicide-rate decline than in control neighborhoods, 2003–2008Quasi-experimentalRead case - WorkedTransport & mobility
Fortaleza's lower speed limits
ChallengeFortaleza had some of Brazil's highest rates of traffic deaths.
Cutting speed limits on the city's deadliest roads, backed by enforcement.
−68%fatal crashes on roads with lower speed limitsObservationalRead case - WorkedTransport & mobility
Vision Zero road safety policy in Sweden
ChallengeHundreds of people were killed on Swedish roads every year, and blaming drivers had stopped working.
Sweden made zero road deaths the legal goal and redesigned roads so crashes don’t kill.
221road deaths in 2019, down from about 540 a year in the late 1990sObservationalRead case - WorkedTransport & mobility
Daylighting and Vision Zero in Hoboken, New Jersey
ChallengeDense streets packed with parked cars made it hard for drivers and walkers to see each other at crossings.
Hoboken used cheap posts at corners, signal changes and lower speeds to stop traffic deaths.
7 yrswithout a traffic death, as of early 2024ObservationalRead case - WorkedTransport & mobility
Car-free city centre in Pontevedra, Spain
ChallengeThe historic centre was clogged with cars, and residents and shops were leaving.
Pontevedra banned through traffic and surface parking from its centre and slowed cars everywhere else.
−97%motor traffic in the historic centre since 1999ObservationalRead case - WorkedTransport & mobility
Rapid build-out of a protected bike network in Seville
ChallengeAlmost nobody cycled in Seville, and the few scattered bike paths did not connect.
Seville built a connected network of separated bike tracks in about five years.
9%cycling share of vehicle trips by 2011, from near zeroObservationalRead case - WorkedTransport & mobility
Congestion charge trial and referendum in Stockholm
ChallengeHeavy rush-hour congestion in central Stockholm, with most of the public opposed to road tolls.
Stockholm trialled a time-varying cordon charge for seven months, then let voters decide.
−20%traffic across the charging cordonObservationalRead case - WorkedTransport & mobility
Traffic circulation plan in Ghent, Belgium
ChallengeAbout 40% of motor traffic in the city centre was just passing through.
Ghent split its centre into sectors that cars cannot drive between, ending through traffic overnight.
−12%rush-hour car traffic in the first yearObservationalRead case
Mixed results
- MixedTransport & mobility
Bogotá's TransMilenio bus rapid transit
ChallengeBogotá needed fast, high-capacity public transport but couldn't afford a metro.
Metro-style bus lines with dedicated lanes and stations, at a fraction of the cost of rail.
43,000passengers per hour per direction measured, averaging 150 per busObservationalRead case - MixedTransport & mobility
London's congestion charge
ChallengeTraffic congestion in central London was severe and getting worse.
A daily fee to drive into central London during working hours.
−18%traffic entering the zone in the first yearObservationalRead case - MixedTransport & mobility
Fare-free public transport for residents of Tallinn
ChallengeThe city wanted to cut car use and make it easier for low-income residents to get around.
Tallinn made buses, trams and trolleybuses free for registered residents in 2013.
+14%public transport use one year after fares were droppedQuasi-experimentalRead case - MixedTransport & mobility
Germany’s 9-euro monthly public transport ticket
ChallengeEnergy prices spiked in 2022, and the government wanted to ease costs and get people out of cars.
For three months, a 9-euro ticket gave unlimited local and regional transit travel across Germany.
+35%rail trips, while car traffic fell just 1–5%Quasi-experimentalRead case
What didn't work
- Didn't workTransport & mobility
Hoy No Circula driving restrictions in Mexico City
ChallengeMexico City had some of the worst air pollution in the world, much of it from cars.
Mexico City banned most cars from driving one weekday a week, based on the last digit of the plate.
Over $300 millionestimated yearly cost to drivers, with no measured air quality gainQuasi-experimentalRead case - Didn't workTransport & mobility
California high-speed rail cost overruns and delays
ChallengeThe state wanted a fast, low-carbon alternative to driving and flying between its largest cities.
California set out to link San Francisco and Los Angeles by high-speed rail; costs more than doubled.
$77bn2018 cost estimate, up from about $33bn pitched in 2008ObservationalRead case