To mitigate the traffic congestion at merging sections in urban expressway networks, a dynamic lane operation is being studied in Japan, which dynamically switches one lane to either approach of a merging section with more traffic demand. To evaluate the safety concern, the lane-change behavior when one lane is closed by variable barrier that is informed by variable message sign (VMS) is analyzed in this study. A driving simulation experiment is conducted for the analysis considering the implementation of the dynamic lane operation for merging sections at Route C1 of Tokyo Metropolitan Expressway. Traffic condition and the distance between a lane-closure point and the VMS are considered as critical factors affecting the risky behavior, and their influence on the lane change behavior is studied.