Are pricing policies effective to change car use?

The effectiveness of transport pricing was considered in two studies regarding intended changes in car use if pricing policies were implemented. In the first study, respondents kept a travel diary for four days, noting all their car trips. Next, they indicated to what extent various pricing policies would affect the trips noted in the diary. In the second study, respondents indicated their intention to
change their car use for various types of trips if pricing measures were implemented. By using tailored questionnaires, accurate feedback was provided about the financial consequences of pricing for each respondent separately.
Results revealed that under pricing policies most people did not intend to change their car use. Pricing policies were relatively more effective when prices increased significantly. Especially visiting and shopping trips were affected, while commuting trips were hardly affected. Moreover, respondents were most likely to reduce their car use for short trips, which are an important source of CO2
emissions and local air pollution.