​​Bike-sharing can make big dent in tailpipe emissions​, SFU study finds

Five highly used bikes could take emissions from one fossil fuel car off Vancouver's road, according to Simon Fraser University researchers who say increasing bike-share networks can play a big role in curbing emissions.

A new study found more than half of the city’s bike-share trips replace car trips, with each bike reducing annual CO₂ emissions by up 120 kilograms (kg) per year. Researchers say that number jumps to nearly 400 kg if those same bikes were used more times per day.

“We calculated each bike in Vancouver’s fleet makes almost two and half trips per day. In terms of emissions impact, it takes 18 bikes to remove tailpipe emissions from one gas-powered car,” says Vahid Hosseini, lead author of the study and a professor in the School of Sustainable Energy Engineering. 

“That’s pretty good, but if those bikes were used eight times a day, it would only take five bikes for every one fossil fuel car and reduce tailpipe emissions by more than three per cent—all without adding a single bike-share station or bike to the fleet.”

Published in Case Studies on Transport Policy, the study used datasets from Mobi by Rogers, the City of Vancouver and TransLink to build emissions models, traffic simulations, and life-cycle assessments. 

Researchers used bike trip data to distinguish between commute and leisure rides, and trip diary data to determine if a bike replaced a journey previously made by car, public transit, or another mode of transportation. 

Then, the team applied an established modelling system called MOVES to calculate emissions reductions for bike trips that replaces car trips. MOVES estimates air pollution emissions and energy consumption based on vehicle type, geographical area, road type, and vehicle age.

At Vancouver’s current use rate of 2.4 trips per bike, per day, researchers discovered the existing bike-share system reduces an estimated 298 tonnes of CO₂ annually. The climate benefits add up quickly in a more highly utilized network, Hosseini says. 

By quantifying climate benefits with direct bike-to-car ratios for the first time, he hopes this research will help cities design more connected and efficient transportation networks.

“Electric vehicles are still a key part of decarbonization, but we’re still struggling with traffic congestion, increasing pressure on infrastructure, and the slow rollout of electric vehicle charging networks,” says Hosseini. “Micromobility like bike-sharing offers a cost-effective and immediate solution to bridge this gap.”