Abstract: Seismic performance of tunnels during earthquakes in densely populated areas requires assessing complex interactions with existing infrastructure such as bridges, metro stations facilities, and low- to medium-rise buildings. This has become more challenging because the distance between surface and underground structures has been shortened to optimize the urban environment functionality. This is even more important in transit transfer stations, which usually comprise tunnels, bridges, and buildings, in which wave propagation interference is exacerbated. Key insights gathered from instrumentation of actual structures and numerical parametric studies are presented. A metro station currently under construction, located near by a 5-story masonry building, was selected as a test site for seismic instrumentation. The site is in Mexico City, in the so-called hill zone, where very cemented sandy silt and silty sands is found. An arrangement of five accelerometers were deployed, to assess free-field, near-field, and building seismic response. Some of the results gathered from the seismic instrumentation after recording five low- to high-magnitude earthquakes from both interface and intraplate events are commented. Major findings of the parametric studies are also highlighted. Three-dimensional finite difference models were developed using the software FLAC3D. Initially, the static response of the tunnel was evaluated accounting for the excavation technique. Then, the seismic performance evaluation of the tunnel was carried out, computing ground deformations and factors of safety, considering soil nonlinearities. Good agreement was observed between predicted and observed damage during post-event site observations during actual earthquakes. Once the soundness of the numerical model was established, a numerical study was undertaken to investigate the effect of frequency content in tunnel-induced ground motion incoherence for tunnels built in cemented stiff soils, considering both intraplate and interplate earthquakes, to assess the effect of differences in their frequency content, duration, and intensity. Multiple scenarios were considered in the numerical study, and the relative distances among the structures were varied to investigate both detrimental and beneficial interaction effects, and to identify the zone of influence where this interaction leads to ground motion variability.