Car-sharing can have a low administrative and technical burden and, although it could have an associated financial burden if incentives are offered to individuals or companies to operate, there are significant savings to be obtained through reducing the number of cars on the road. Congestion is estimated to cost the EU economy €100 billion annually, with a US study indicating that if car-sharing schemes were widely adopted vehicle numbers could be reduced by one-third in specific scenarios.^[5]

The first barriers that need to be overcome when it comes to car-sharing are the reluctance of potential users to adopt car-sharing services and a strong desire for car ownership. To overcome these barriers, it is important to generate awareness and change aspirations from single car ownership to the use of connected transport modes, through robust awareness campaigns and measures tackling user behaviours.

Car-sharing may not necessarily have a major impact on overall levels of car use in a city, and further infrastructure for cars may have to be provided that is specific to self-service sharing schemes. Moreover, the effect of ride-hailing apps on congestion is contested. They could reduce traffic by encouraging people to leave their cars at home, or they could increase the number of vehicles on the road if people switch away from public transport or forms of active mobility

In the case of ride-sharing schemes it is also important that, for passenger safety, the appropriate insurance is in place and that there are procedures for driving licence checks.

A further challenge relates to restrictions on private vehicles that pose a threat to car-sharing. Exemptions from such policies could be a way to promote car-sharing.

It is difficult for self‑service car-sharing schemes to generate a user base that is large enough to reach a reasonable operational scale, and competition from competitively priced taxis has been found to reduce the use of such schemes.^[6]  The Autolib’ electric car-sharing scheme, which operated in Paris from 2011 to 2018, offers some important lessons for other cities in this regard. The service had to compete with a minicab service, it suffered from poor maintenance by users, and the vehicles became places of refuge for drug users. As a result of declining use of the service, the operating company became insolvent and stopped operating.

Shared transport schemes may face resistance from traditional taxis. In the United States of America, ride-sharing had a market share of just 8 per cent in 2014; however, four years later, it commanded 70.5 per cent of the market, with taxis accounting for just 6 per cent. This can have adverse effects on taxi drivers’ livelihoods, especially for those who already face financial challenges.^[7] This can be mitigated by offering them skills training or access to entrepreneurship opportunities. A mixed regulatory mechanism that allows competition between ride-sharing and taxis can also be developed to address any regulatory asymmetry.

In order to be successful, it is important that the operators of car-sharing schemes understand the policy context and regulatory frameworks of the cities where they plan to launch. For example, DriveNow – a car-sharing scheme with 1 million registered users across multiple cities and countries – has had to stop operating in Stockholm owing to high congestion charges and parking costs. ^[8][9]

Meanwhile, ride-sharing apps such as Uber have encountered resistance from the public owing to their employment practices, leading to bans on taxi and ride-sharing apps in some countries and cities. Solutions to this issue can include labour law reforms for self-employed workers and regulations on the mandatory installation of meters. Furthermore, such apps require a strong and reliable mobile network, with reasonable costs for data use. Economies in the southern and eastern Mediterranean have particularly weak data networks, with Jordan, Lebanon, Morocco and Tunisia all in the lowest third of countries globally for overall data speeds.^[10]

Elsewhere, the Los Angeles Metro is working with car-sharing company Getaround to provide an affordable and “hassle-free” car-sharing service at more than 25 Metro transit park-and-ride sites.^[11]

In the absence of a robust legal framework encompassing rules on the parking and riding of micro‑mobility vehicles, improper parking of such vehicles can creates obstacles for blind and partially sighted pedestrians and people with other disabilities. Moreover, with electric micro-mobility vehicles there is also the problem of recycling batteries at the end of their life. If the private companies offering e-mobility services do not operate a sound recycling system, their negative environmental impact could offset the CO₂ emissions that are saved by using those vehicles. In the United States, Lyft is partnering with Redwood Materials, a battery recycling company, to ensure that the batteries from its fleets of shared e-bikes and e-scooters do not end up in landfill at their end of their life. Moreover, in most cities micro-mobility schemes are not inclusive: city-sponsored across the United States reveal that people who use micro-mobility solutions tend, on average, to be younger, single and male, with higher levels of income.^[12]

In Paris, city authorities have taken action in relation to free-floating e-scooters by establishing a code of conduct while waiting for the adoption of a new legal framework at national level. All e‑scooter operators in the city were invited to join the working group for that code of conduct, which established guiding principles and paved the way for good public-private collaboration. ^[13] Thus, municipal authorities and industry leaders have to collaborate in order to ensure that micro-mobility schemes benefit all citizens (not just specific populations or districts) and minimise the risks (both environmental risks and risks to personal safety) that can arise from the use of such solutions.