Transportation structures such as bridges and culverts are known to inadvertently provide roosting and nesting habitat for a wide variety of wildlife species, including crevice-dwelling bats and birds such as swifts and swallows. Such species, here referred to as structure-dwelling species, nest and roost within the hinges, joints, crevices, and cavities and on ledges of transportation structures. For structure-dwelling species that have experienced habitat losses, anthropogenic habitats may be especially important for species survival. Such habitat may provide important shelter and breeding habitat as well as important migratory stopover and overwintering habitat. Structure-dwelling species are not always welcome in transportation facilities due to conflicts with adjacent facilities, proposed facility maintenance, agency access requirements, and other proposed activities and improvements that may disturb or harm wildlife and require regulatory compliance or mitigation. Despite such conflicts, bat and bird habitat features are sometimes deliberately incorporated into structure design or added via structure retrofit. These habitat elements may be voluntarily implemented to enhance species habitat or may be implemented as mitigation to compensate for impacts on species. Habitat elements are most advantageous when located in areas spanning or adjacent to aquatic resources and open space, and not located within high disturbance areas such as over a busy roadway. Wildlife crossings are regularly developed worldwide and are increasingly being adopted as part of standard transportation design and mitigation practices. Such structures are designed for wildlife, are typically located in low disturbance environments, and aim to connect areas of open space to facilitate wildlife and ecosystem connectivity. I propose that wildlife crossings provide a unique opportunity to provide important supplementary habitat elements for structure-dwelling species. Incorporation of such habitat elements within wildlife crossing structures would increase the availability of habitats that are increasingly rare (e.g., snags, crevices, caves, rocky outcroppings), reduce wildlife conflict with DOTs, and provide a habitat surplus mechanism not obtainable via traditional policy such as CEQA and SEPA, which only require mitigation to pre-project (rather than historical) habitat conditions. Such habitat features can be implemented with little to no additional cost and can be included in new construction (e.g., hinges, joints, closure pores, ledges) or can be incorporated as retrofits (e.g., Oregon Wedge bat boxes). Consideration of such habitat elements facilitates a fresh and more comprehensive approach to how we design wildlife crossing structures and integrate conservation into the built environment. Additionally, the added conservation value and low cost of incorporating habitat elements within wildlife crossing structures provides additional beneficial value above and beyond traditional design approaches.