Across the United States, bike movements are advocating for infrastructural changes to streets. Sustainable transport advocates and researchers expect that reshaping built environments will increase bicycle usage because people will feel safer riding with more cycling facilities in place. These strategies identify road design as the key factor in how people use streets. From an ethnographic perspective, cycling research should also consider how road users create meanings in transit. This paper looks beyond physical changes to space and explores how “human infrastructure” encourages or discourages bicycling. Tacking between observation and participation, cultural anthropology can help design experimental spaces, such as Los Angeles’ CicLAvia, that offer diverse city inhabitants an opportunity to reflect on their transport habits in situ. Experimental spaces for bicycling show that human infrastructure shapes transportation behavior, and has the potential to change it. This paper contributes to a growing ethnographic literature in mobilities research.