Environmental impacts of shared mobility: a systematic literature review of life-cycle assessments focusing on car sharing, carpooling, bikesharing, scooters and moped sharing

ABSTRACT Evidence about the environmental impacts of shared mobility is fragmented and scattered. In this article a systematic literature review is presented. The review focuses on assessments that use Life-Cycle Assessment to quantify the environmental impacts of car sharing, carpooling, bikesharing, and scooter/moped sharing. The results of these assessments were analyzed, as well as the factors that influence these impacts. Business-to-consumer car sharing, peer-to-peer car sharing, carpooling, bikesharing, and scooter/moped sharing can all cause gains and losses in terms of changing the environmental impacts of passenger transportation. The findings presented here refute unconditional claims that shared mobility delivers environmental benefits. Factors that influence changes in environmental impacts from passenger transportation from shared mobility include travel behaviour, the design of shared mobility modes, and how such schemes are implemented, as well as the local context. Local governments and shared mobility organisations can benefit from the analysis presented here by deepening their understanding of these factors and considering the life-cycle phase where the greatest impacts are caused.


Manufacturing
Use Maintenance (Rebalance) Evaluation of the actual bike sharing system and three scenarios that assessed changes in the fleet size and the rebalancing strategy.
Scenario based with sensitivity analysis that focus on two variables rebalancing frequency and fleet size.
The rebalancing strategy was modelled in the scenarios, while the fleet size was modelled during the sensitivity analysis.SC1 -Rebalance the system once a day SC2 -Rebalance the system two times per day SC3 -Rebalance the system three times per day The scenario with lowest emissions is the one that is balanced once a day, too little or too big fleet increases the emissions.Inefficient rebalancing cannot be compensated by small fleets.The increase in the impacts is due to the short lifetime the e-scooters have in the shared system.The sensitivity analysis shows that the lifetime of the scooters is a very important variable to consider when assessing impacts.When comparing the personal scooter with a shared one the results show that personal scooters preform better due to a longer life time and better usage 10.3390/su12051 803 10 E-scooters NA Fine particulate matter Air quality City Europé

Production Use
Comparison of scenarios where the baseline is considered.The modal shift and extended lifetime in the shared system The paper doesn't clarify what the base case represents.
The increase in the impacts is due to the short lifetime the e-scooters have in the shared system.The sensitivity analysis shows that the lifetime of the scooters is a very important variable to consider when assessing impacts.When comparing the personal scooter with a shared one the results show that personal scooters preform better due to a longer life time and better usage The increase in the impacts is due to the short lifetime the e-scooters have in the shared system.The sensitivity analysis shows that the lifetime of the scooters is a very important variable to consider when assessing impacts.When comparing the personal scooter with a shared one the results show that personal scooters preform better due to a longer life time and better usage The increase in the impacts is due to the short lifetime the e-scooters have in the shared system.The sensitivity analysis shows that the lifetime of the scooters is a very important variable to consider when assessing impacts.When comparing the personal scooter with a shared one the results show that personal scooters preform better due to a longer life time and better usage The docked and dockless bikes had a higher impact than private due to the electronics that are used.The dockless performed worse due to rebalancing.In order to present sustainability gains the shared bike must replace a certain amount of travelled km by car, if the bike sharing system is replacing private bike or walking then impacts are negative.The investigate the length of the trips by bike and then modelled energy savings for trips who's lengths was more than 1 km.They assume that these trips were done by taxi.Thus they compare taxi driving and bike sharing.
Not surprising that the results show a decrease.Comparison of before and after carsharing was introduced using results from a survey They measure direct impacts (due to changes in travelling behavior ) and full impact (forego a vehicle).Direct impacts have a low level of uncertainty and full impacts a higher uncertainty.This was calculated considering results from a survey.The main metric is changes in VKT in the households Users that gain access to a car increase their emissions.Users that forego a car decrease the.If this is quantified at a total level then there are environmental gains.They conducted a survey to the users of car sharing in Palermo and their findings point out to the fact that car sharing replaces the purchase of a second vehicle and that the modal share changes.They report they travel the same amount of km.After they took this information and calculated emissions saved considering the characteristics of the average car and the car from CS.
The cars in the car sharing fleet present better performance than private owned vehicles.There was a decrease of emissions but this decrease is limited.https://doi.They conducted a survey to the users of car sharing in Palermo and their findings point out to the fact that car sharing replaces the purchase of a second vehicle and that the modal share changes.They report they travel the same amount of km.After they took this information and calculated emissions saved considering the characteristics of the average car and the car from CS.
The cars in the car sharing fleet present better performance than private owned vehicles.There was a decrease of emissions but this decrease is limited.
https://doi.They conducted a survey to the users of car sharing in Palermo and their findings point out to the fact that car sharing replaces the purchase of a second vehicle and that the modal share changes.They report they travel the same amount of km.After they took this information and calculated emissions saved considering the characteristics of the average car and the car from CS.
The cars in the car sharing fleet present better performance than private owned vehicles.There was a decrease of emissions but this decrease is limited.
https://doi.They conducted a survey to the users of car sharing in Palermo and their findings point out to the fact that car sharing replaces the purchase of a second vehicle and that the modal share changes.They report they travel the same amount of km.After they took this information and calculated emissions saved considering the characteristics of the average car and the car from CS.
The cars in the car sharing fleet present better performance than private owned vehicles.There was a decrease of emissions but this decrease is limited.
https://doi.Comparison of before and after carsharing was introduced in a city during one year They build scenarios for car-sharing where they consider the speed, the type of driving cycle and other variables.They calculated WTW emissions.In the simulations they include different type of vehicles to see how this would improve the system.
As the fleet is today there are environmental benefits from car sharing.However, these benefits increase considerably when the fleet changes to hybrid or to electric.Assessment of e-moped system considering three different sizes (2500, 10000 and 50000) and energy sources (current and renewable).
The study explores using an agent base the probability that escooters will replace trips done by private cars.They found that depending on the fleet size the percentage of shared cars that can be replaced varies.Larger fleets lead to more replacement but to more impacts from production and less from rebalancing.Assessment of e-moped system considering three different sizes (2500, 10000 and 50000) and energy sources (current and renewable).
The study explores using an agent base the probability that escooters will replace trips done by private cars.They found that depending on the fleet size the percentage of shared cars that can be replaced varies.Larger fleets lead to more replacement but to more impacts from production and less from rebalancing.Assessment of e-moped system considering three different sizes (2500, 10000 and 50000) and energy sources (current and renewable).
The study explores using an agent base the probability that escooters will replace trips done by private cars.They found that depending on the fleet size the percentage of shared cars that can be replaced varies.Larger fleets lead to more replacement but to more impacts from production and less from rebalancing.Small size fleets and renewable energy have the lowest impacts 10.3390/wevj120 30096 Car-sharing Car-sharing/Ridesharing Several impacts na Country Europé

Manufacture Use EoL
Evaluation of the impacts of electrification of the fleet in the UK.An additional scenario was developed where sharing was considered as an alternative This study focus on the electrification of the fleet in UK, then a second scenario is build to assess impacts of both electrification and sharing over time.Extracting data from this paper was not possible because they present a graph but the number that this graph represent are not specified.
Observing the general trend of the graphs not surprisingly there is a decrease in impacts if people shared their vehicles.
where the baseline is considered.The modal shift and extended lifetime in the shared systemThe paper doesn't clarify what the base case represents.
The investigate the length of the trips by bike and then modelled energy savings for trips who's lengths was more than 1 km.They assume that these trips were done by taxi.Thus they compare taxi driving and bike sharing.This articles uses data from Didi when it offers the service of carpooling.This article includes the results of 10.3390/en11113214.In addition to this data, they applied a survey where they ask users changes in modal shift and ownership.Changes in modal shift were modelled in the LCA and changes in ownership were modelled with IO This articles uses data from Didi when it offers the service of carpooling.This article includes the results of 10.3390/en11113214.In addition to this data, they applied a survey where they ask users changes in modal shift and ownership.Changes in modal shift were modelled in the LCA and changes in ownership were modelled with IO To model changes in environmental impacts they explore changes in vehicle ownership, VKT, parking infrastructure and modal shift.All these assumptions were taken from other studies and they build three scenarios (low, middle and high) Most of the environmental gains come from changes in ways of travel.
The model excludes impacts from rebalancing 10.1016/j.apenergy.2018.03.101This articles uses data from Didi when it offers the service of carpooling.This article includes the results of 10.3390/en11113214.In addition to this data, they applied a survey where they ask users changes in modal shift and ownership.Changes in modal shift were modelled in the LCA and changes in ownership were modelled with IO Changes from modal shift and car ownership are present in the They conducted a survey to the users of car sharing in Palermo and their findings point out to the fact that car sharing replaces the purchase of a second vehicle and that the modal share changes.They report they travel the same amount of km.After they took this information and calculated emissions saved considering the characteristics of the average car and the car from CS.
They build scenarios for car-sharing where they consider the speed, the type of driving cycle and other variables.They calculated WTW emissions.In the simulations they include different type of vehicles to see how this would improve the system.As the fleet is today there are environmental benefits from car sharing.However, these benefits increase considerably when the fleet changes to hybrid or to electric.