Colorado Department of Transportation (CDOT) bridge engineers are redesigning bridge tub girders to prevent homeless encampments from forming inside the structures [1].

These design changes aim to reduce the recurring financial and operational burden of maintaining public infrastructure in the Denver metropolitan area. By curbing access to the interior of bridge supports, the state seeks to minimize the need for frequent and costly sanitation interventions.

Engineers are specifically targeting tub girders, which are hollow structural components that have inadvertently provided shelter for people experiencing homelessness. These spaces often become makeshift encampments, leading to the accumulation of waste and debris within the bridge framework [1].

The shift in design comes after a period of significant expenditure on maintenance. CDOT has spent more than $300,000 cleaning out overpasses in the Denver area over the past five years [1]. This spending reflects the ongoing challenge of managing public spaces that are utilized for residential purposes.

The agency is now integrating deterrents into the engineering phase of new projects and modifications. This approach moves the strategy from reactive cleanup to proactive prevention, a shift intended to preserve the integrity of the infrastructure.

While the specific engineering modifications were not detailed, the goal remains the elimination of accessible voids that can be used as shelters. The effort is part of a broader struggle in the U.S. to balance the management of public infrastructure with the needs of the unhoused population [1].

“CDOT has spent more than $300,000 cleaning out overpasses in the Denver area over the past five years.”

This move represents a trend toward 'hostile architecture,' where urban design is used to guide or restrict human behavior. By modifying the physical structure of bridges to prevent habitation, CDOT is prioritizing infrastructure maintenance and cost reduction over the provision of sheltered spaces, highlighting the tension between city management and the homelessness crisis.