The blocking of a lane in one direction on an urban two-lane road (referred to as bottlenecks in this paper), receives little attention in current research, although it is a common scenario in traffic. In order to enable automated driving in this situation in the future, this research gap must be closed. An online study with 86 test persons collects data on gap acceptance at bottlenecks and the user experience and user acceptance of an automated cooperative bottleneck assistant. The participants watched videos created with the microscopic traffic flow simulation software PTV Vissim. They experienced the bottleneck situation from different perspectives and varying oncoming traffic without and with a cooperative bottleneck assistant. The results show that gap acceptance is distributed over a number of time gaps and depends on the individual driver. A time gap of 10 seconds, however, gets accepted in 73.5 % of all cases. The evaluation of the automated assistant shows that the test persons feel less secure with an assistant than they would if they had selected the time gap themselves and expected a passive driving style. A human-machine interface also does not increase the feeling of safety but is nevertheless expected. ... mehrThese results form a basis for the further development of a bottleneck assistant and can be used to calibrate a microscopic traffic flow simulation of such bottlenecks.