Introduction 

Transit-oriented development (TOD) is a planning strategy that promotes high density, mixed-use (residential and commercial) development centered around public transportation services. The goal of TOD is to increase access to housing, retail, education, healthcare, and park space by placing those resources in close proximity to transit, typically within walking distance.   

While TOD can improve access to resources, new developments can also pose risks of higher housing prices, gentrification, and displacement of lower-income communities. As a result, governments have turned to equitable TOD (ETOD), with the goals of ensuring that all people can live near transit and providing more inclusive access to opportunity. A key element of ETOD is incorporating affordable housing.  

Communities seeking the fiscal, social, and environmental benefits of TOD with on-site affordability can benefit from practical mechanisms to encourage this development strategy. Eno is launching a new series that will examine how metropolitan areas across the country are approaching this work, including how agencies coordinate across housing, land use, and transportation, what tools they use, and what constraints they encounter. This research draws on interviews and publicly available information. Each case study will highlight the region’s experience with TOD and housing, development of equitable TOD, barriers faced, and lessons or transferable practices that may be useful elsewhere. Each case study will also provide key resources related to transit-oriented development. This week will begin with Denver and its transit agency, Regional Transportation District (RTD).  

Denver- RTD 

Issues in Housing Affordability  

Housing affordability is a major concern in the Denver metropolitan area, which is one of the least affordable regions in the U.S., for both renters and homebuyers. A 2025 poll conducted for the Colorado Health Foundation found that 89 percent of surveyed residents said the cost of housing was an “extremely serious” or a “very serious” problem. The housing cost issues in the Denver area exist despite the high median household income for the Denver metro area ($103,055) and for the city of Denver ($94,157), which are significantly higher than the national average of $77,719.   

Data from the National Association of Realtors and the National Low Income Housing Coalition supports the fact that Denver is facing a housing affordability crisis. The National Association of Realtors’ Housing Affordability Index measures whether the typical family in each region earns enough income to qualify for a mortgage loan on a typical home. An index above 100 signifies that a family earning the median income has more than enough income to qualify for a mortgage loan on a median-priced single-family home, assuming a 20 percent down payment. The index for Denver is 80, e.g. below that threshold of affordability. Table 1 compares selected metropolitan areas and shows that the typical family in the Denver region is much less likely to earn enough income to qualify for a mortgage on a typical home. 

Table 1. Housing Affordability Index 

Denver is also a region where relatively few rental properties are available for low-income households. According to the National Low Income Housing Coalition, only 37 rental units are affordable and available for every 100 renter households (these households refer to households that make below 50 percent of the median area income in the Denver area). The number of units across all major U.S. metropolitan areas is 53. Faced with a growing population, the transit agency in the region has taken the opportunity to provide valuable transit-oriented development.  

RTD and its work in TOD 

The Regional Transportation District (RTD) provides bus and rail service throughout the Denver metropolitan area—one of the geographically largest transit service areas in the United States, at over 2,342 square miles. In 2004, the region’s voters approved a sales tax to fund one of the nation’s largest transit expansion programs, with the goal of encouraging growth along a new rail network. Since that time, there has been a significant concentration of growth near the region’s transit lines.  

RTD also operates more than 80 park-and-ride lots with over 37,000 parking spaces, and many of them are underused. For example, Wadsworth Station has a garage that can accommodate approximately 1,000 cars and was only 28 percent full in 2019, even before ridership plummeted during the COVID-19 pandemic. The agency’s largest park-and-ride lots each have more than 1,000 spots, and none of them were more than 60 percent full in early 2024. With TOD a priority, RTD identified these underutilized transit-adjacent properties as an asset and began collaborating with private developers to convert surface parking lots into mixed-use developments that integrate residential, commercial, and transit functions.  

RTD’s ETOD Policy 

In 2021, the RTD Board approved an equitable TOD policy whose goal is to “encourage affordable residential development for low-income households at and along high-frequency transit stations and corridors.” The policy is expected to generate revenue through joint development on RTD real property, increase transit use, and enhance community relationships. RTD uses the Federal Transit Administration’s definition of “joint development” as a partnership between a transit agency and a developer to improve agency property at an active transit facility. Joint development includes air rights development, ground lease arrangements, and sale of land. 

The policy focuses on setting affordable housing goals and reducing the costs of development of affordable housing by: 

• Setting a goal to have 35 percent of total residential housing units developed on RTD property between 2021 and 2031.  

• Reducing the number of parking spaces that developers must replace 

• Considering the potential for shared parking 

• Expediting internal reviews of developer proposals and potentially waiving processing and development review fees. 

• Considering the development’s full benefits when calculating sale/lease price 

Low-income households use transit more: Before implementing the policy, RTD surveyed residents of 35 station-area apartments across the region and found that low-income households typically use buses and trains more than market-rate residents. This has given RTD an incentive to prioritize low-income housing near its stations.  

Affordable Housing Goal: RTD set a non-binding goal that 35 percent of all housing developments built on RTD property from 2021 to 2031 be affordable to low-income households (as defined by the Colorado Housing and Finance Authority). This goal is aspirational and non-binding. For each project, RTD works with the local government to set an affordable housing goal. If it is determined that affordable housing is not feasible or contradicts local governmental entities’ adopted plans, zoning or regulations, then no goal is established. 

Benefits of establishing ETOD policy: When the RTD’s Board of Directors adopted its policy, the media attention generated a great deal of interest and conversations with developers, and improved RTD’s reputation among many residents and policy makers. Furthermore, TOD efforts garnered more support and resources from departments within the agency. The policy’s rollout not only attracted developers eager to participate in transit-oriented projects but also led to a notable increase in internal support and resources for TOD initiatives within the agency. 

Prior to 2024, RTD was not permitted to sell or lease property for less than Fair Market Value. This prohibition was lifted in 2024, and RTD updated its ETOD policy in 2025 to reflect this change. The policy now includes information that allows the agency to negotiate land price reductions if developers include affordable housing, limit parking, offer multiple bedroom sizes, and include below market rate retail that prioritizes local businesses.  

Evaluating TOD Projects and Prioritizing RTD’s Sites 

RTD has two basic goals regarding TOD projects on its properties: increasing revenue and ridership. Revenues are generated through ground lease of its land (the agency will sell its land only in the rare instances where leases are infeasible). When evaluating projected ridership impacts, RTD compares ridership that might be lost by reducing parking with the expected ridership increase generated by a new development.  

In addition to revenue and ridership, potential developments must meet minimum impact thresholds in regard to transit operations, maintenance, safety, security, the local jurisdiction’s preferences for the site, and conform to design best practices. TOD projects are also measured against additional qualitative criteria including affordable housing as well as improved safety, security, upgraded rider amenities and access, community facilities, and enhancing RTD’s brand.  

To determine which sites have the greatest potential, TOD staff consider site size, zoning, parking utilization, infrastructure availability, local market conditions, community interest in redevelopment, and any unique site attributes or challenges.  

Number of Parking Spaces 

Prior to 2021, for projects to build TOD on existing park-and-ride lots, RTD typically required developers to incorporate the same number of new parking spots for transit users into their developments. With the 2021 ETOD policy, RTD can reduce the required number of spaces that must be replaced. Eliminating the requirement that developers had to replace each parking space was a fundamental change for RTD. The agency had been hesitant to make this change because parking spaces were an important part of the original transit system design, and some RTD officials were concerned that the unused space might be needed in the future. On the other hand, reducing the cost associated with building more parking makes projects more financially feasible.  

Additionally, RTD’s own research indicated that residential developments near station areas typically have more parking spaces than needed at peak times. Before adopting its ETOD policy, RTD staff analyzed 86 private station-area properties across the region and found that residents used only 58 percent of all parking spaces provided at peak times. At income-restricted housing, only 50 percent were used. This research enabled RTD to adopt the policy to allow developments with affordable homes to provide fewer parking spaces (per unit) than those with market-rate homes. 

Barriers to TOD and Affordable Housing 

Not all locations have proven feasible to redevelop as ETOD. Some communities outside of Denver have expressed concerns about higher-density development and affordable housing units. Setting a minimum share of affordable units in residential projects, per Denver’s inclusionary housing requirement, can result in developers increasing prices for market-rate units to offset the cost of affordable units, which can impact the overall project feasibility. Site conditions also limit opportunities in certain locations, as some RTD park-and-rides are constrained by geography and lack the infrastructure and surrounding land uses typically needed to support TOD. 

Key Lessons 

Examine Existing Assets 

• A region with a new rail system, mostly built in and near freight rail corridors and highways, can be transformed into serving a growing population living and working near stations.  

• Underutilized park-and-rides and other properties can be converted into revenue-generating assets that help achieve TOD goals 

Use Data to Inform Decisions  

• The political decision to reduce parking had caused years of hesitation. Armed with nuanced data on park and ride usage, RTD is now open to reducing the number of parking spaces that developers must replace when they build on RTD parking lots. 

• RTD research indicated residents of affordable units were less likely to own a car and more likely to use transit services. 

• RTD’s research also indicated that residential developments near station areas have more parking spaces than needed at peak times.  

Recognize the Many Benefits of TOD 

• A transit agency that encourages residential development for low-income households can generate more revenue, increase transit use, and enhance community relationships. 

• When an agency adopts a TOD policy, it can generate a great deal of interest and conversations with developers, improve its reputation among many residents and policy makers, and obtain more support for TOD projects from departments within the agency. 

•  A law mandating local governments to adopt TOD supportive zoning near stations can be an impetus for new projects. 

Make Time for Coordination 

• Numerous agency departments need to be consulted on TOD projects, including those related to real estate, maintenance, operations, planning, engineering, finance, legal, safety, and security. 

• TOD staff in an agency need to overcome silos within their agency in both informal and formal ways (e.g., attending meetings and social events, educating staff, etc.) 

Consider How to Provide Flexibility 

• Requiring a transit agency to receive fair market value for its land can make it harder to build affordable housing on its property.  

Resources 

For more information on Denver’s approach to affordable housing, Table 2 below provides links to RTD resources including policies, processes, and reports related to its TOD and affordable housing work.  

Table 2: Resources related to RTD’s TOD and Affordable Housing efforts