climate analytics


Policy measures

Increasing load factor for passenger cars

Car pooling

Carpooling refers to a practice where passengers travelling on the same route share one car instead of driving alone. Carpooling may apply to regular commuting or irregular intercity travels, even across borders. Social media (e.g. Facebook) and private initiatives (e.g. Blabla car or Telekocsi) have been very effective in coordinating such travels.  

In terms of intercity travels, carpooling may, in most cases, compete with less carbon intensive modes of transport, e.g. trains or cycling. Therefore, the impact of additional effort on promoting this kind of car pooling on emissions reduction may be doubtful.  

car pooling

Contrary to this, carpooling for regular commuting, especially to work places which may not be well connected by public transport, should be strongly encouraged. This may take the form of the employers taking the initiative or facilitating the creation of an exchange platform that would make it easier for employees to find the optimal carpooling alternative. Cars used for carpooling should also receive preferential treatment, e.g. in access to parking space closer to the entrance or charging station for electric vehicles. Finally, the shifts of the employees should take into consideration the carpooling needs, e.g. employees using the same carpooling option should be allowed to start and finish work simultaneously, if possible. Such practices should be strongly encouraged by adequate tax policy.    

A special case of carpooling concerns is transboundary commuting. In this case, the distances that the employees are ready to travel are much larger, often due to significant differences in wages. At the same time, public transport options are mostly non-existent. Especially in this case, the employees should take into consideration the establishment of regular connections (e.g. by bus) from a point that can be reached by the largest number of employees by their own means of transport. 

Preferring fuller cars

Carpooling can be promoted  through creating favourable conditions for cars with multiple occupants on main city roads as opposed to vehicles with only one occupant. There are several policy options to introduce in order to motivate carpooling and higher occupancy levels in private passenger vehicles, which may take the form of low or no charges on paid roads or bridges, or permissions to use special lanes, e.g. for buses. Specifically these policies could include:

preferring fuller cars
  • The introduction of High Occupancy Vehicle (HOV) lanes on main motorways. Typically these allow passenger vehicles with 2+ passengers to use dedicated lanes or to access bus lanes. They may only be allowed during peak hours, or on specific days, and certain vehicles such as low- or no-emissions cars are often exempted
    • the number of passengers in the car that could qualify a car to benefit from the utilisation of the special lane or low charges should differ depending on the situation
    • It should be noted that the success of HOV lanes in practice may be questionable, and therefore they ought to be combined with other policies to produce the desired effect at the highest possible level.
  • Similarly to HOV lanes, High Occupancy Toll (HOT) lanes are dedicated toll lanes only for high occupancy vehicles, prioritising them over low occupancy vehicles and incentivising carpooling or ride sharing. 
    • A variant of this policy allows permitted access to HOV lanes for single occupancy vehicles upon payment of a fee, which proponents argue both raises revenue and motivates the use of public transport or other lower cost options. Opponents find that this may incentivise those who can afford to pay the fee to drive alone. 
  • Partner with workplaces to introduce initiatives which reduce individual barriers to carpooling and ride-sharing by:
    • facilitating carpool organisation through online matching programs
    • creating parking places or permits specifically for carpooling vehicles and/or reducing fees for said spaces
    • introducing guaranteed ride home programs by partnering with car-share or taxi companies and public transportation to ensure a ride home in case of emergency
    • creating designated pick-up and drop-off points at park and ride locations to facilitate easier ridesharing (see also: the practice of slugging in the Washington D.C. metro area)


Australia established a law in 2017 throughout the whole country which established that transit lanes may only be used by passenger cars carrying more than 1 passenger. Proponents of this policy argued that it would lead to significant reductions in congestion and allow for more flexibility especially in the face of significant population growth at a relatively low cost compared to other interventions. 

In the private sector, Nike works to incentivise carpooling among its employees through the use of an in-house rideshare matching service, prioritised parking for carpooling vehicles, and establishing a guaranteed ride home program in partnership with the local transit authority. In addition, management has also supported the use of flexible working hours to ensure that workers are not penalised for any sort of issue which may come up as a result of carpooling. Nike has been consistently listed as one of the best workplaces for commuters due to their flexibility and innovative policies which prioritise multimodal and less emissions intensive modes of transportation. 

Policy measures