From 2013 until 2021, Bartol served as deputy chairman of the SPD parliamentary group under the leadership of successive chairpersons Thomas Oppermann (2013–2017), Andrea Nahles (2017–2019) and Rolf Mützenich (2019–2021). In the negotiations to form a fourth coalition government under Merkel following the 2017 federal elections, he again led the working group on transport and infrastructure, this time alongside Thomas Strobl and Alexander Dobrindt.
Bartol is a member of the Parliamentary Friendship Group for Relations with the States of Central America, the Parliamentary Friendship Group for Relations with the States of South America – which is in charge of maintaining inter-parliamentary relations with Argentina, Bolivia, Chile, Ecuador, Guyana, Colombia, Paraguay, Peru, Suriname, Uruguay, Venezuela – and the German-Brazilian Parliamentary Friendship Group.
Other activities
Corporate boards
KfW, ex-officio Member of the Board of Supervisory Directors (since 2018)[2]
INOSOFT AG, Member of the Supervisory Board (-2013)
Non-profit organizations
Business Forum of the Social Democratic Party of Germany, Member of the Political Advisory Board (since 2020)[3]