[1] Directive (EU) 2018/2001 of the European Parliament and of the Council of 11 December 2018 on the promotion of the use of energy from renewable sources. Official Journal of the European Union L 328/82, 2018.
[2] European Environment Agency. Use of renewable energy for transport in Europe. [Online]. [Accessed 13. 04. 2021]. Available: https://www.eea.europa.eu/data-and-maps/indicators/use-of-cleaner-and-alternative-fuels-2/assessment.
[5] McKenzie E. C., Durango-Cohen P. L. Environmental life-cycle assessment of transit buses with alternative fuel technology. Transportation Research Part D: Transport and Environment. 2012:17(1):39–47. https://doi.org/10.1016/j.trd.2011.09.00810.1016/j.trd.2011.09.008
[6] Yanzhi Xu., Gbologah F. E., Dong-Yeon Lee., Haobing Liu., Rodgers M. O, Randall L.Guensler. Assessment of alternative fuel and powertrain transit bus options using real-workd operations data: Life-fyfle fuel and emissions modeling. Applied Energy 2015:154:143–159. https://doi.org/10.1016/j.apenergy.2015.04.11210.1016/j.apenergy.2015.04.112
[7] Central Statistical Bureau of Latvia. Mobility Survey of Latvia Population. 2018. [Online]. [Accessed 12. 01. 2021.] Available: https://www.csb.gov.lv/en/statistics/statistics-by-theme/transport-tourism/transport/search-in-theme/357-results-survey-mobility-survey-latvia.
[8] Holmgren J., Ivehammar P. Mode choice in home-to-work travel in mid-size towns: The competitiveness of public transport when bicycling and walking are viable options. Transportation Research Procedia 2020:48:1635–1643. https://doi.org/10.1016/j.trpro.2020.08.20410.1016/j.trpro.2020.08.204
[9] Oña de J., Estévez E., Oña R. Public transport users versus private vehicle users: Differences about quality of service, satisfaction and attitudes toward public transport in Madrid (Spain). Travel Behaviour and Society 2021:23:76–85. https://doi.org/10.1016/j.tbs.2020.11.00310.1016/j.tbs.2020.11.003
[11] Oña de J., Estévez E., Oña R. Public transport users versus private vehicle users: Differences about quality of service, satisfaction and attitudes toward public transport in Madrid (Spain). Travel Behaviour and Society 2021:23:76–85. https://doi.org/10.1016/j.tbs.2020.11.00310.1016/j.tbs.2020.11.003
[16] Baum H. J. Free public transport. The proposal in the Federal Republic of Germany. Journal of Transport Economics and Policy. Journal of Transport Economics and Policy 1973:7(1):3–19.
[17] Urbanek A. Potential of modal shift from private cars to public transport: A survey on the commuters’ attitudes and willingness to switch – A case study of Silesia Province, Poland. Research in Transportation Economics 2021:85:101008. https://doi.org/10.1016/j.retrec.2020.10100810.1016/j.retrec.2020.101008
[18] Holmgren J., Ivehammar P. Mode choice in home-to-work travel in mid-size towns: The competitiveness of public transport when bicycling and walking are viable options. Transportation Research Procedia 2020:48:1635–1643. https://doi.org/10.1016/j.trpro.2020.08.20410.1016/j.trpro.2020.08.204
[20] Urbanek A. Potential of modal shift from private cars to public transport: A survey on the commuters’ attitudes and willingness to switch – A case study of Silesia Province, Poland. Research in Transportation Economics 2021:85:101008. https://doi.org/10.1016/j.retrec.2020.10100810.1016/j.retrec.2020.101008