April 2024 Virtual Public Involvement

Welcome to Our April 2024 Virtual Public Involvement

Thank you for joining us for our first Virtual Public Involvement for the I-25: Speer Boulevard & 23rd Avenue Bridge and Interchange project. Scroll down to learn about the project and to provide your input via the linked survey. 


  Public Open House | April 8, 2024

Join us in person for the Public Open House from 4 to 7 p.m. on Monday, April 8, 2024 at Colorado Department of Transportation Headquarters located at 2829 W Howard Place in Denver, CO 80204. The project team will be available to answer your questions.

April 2024 Open House & Public Involvement Survey


CDOT launched the I-25: Speer Boulevard and 23rd Avenue Bridge and Interchange project during the Summer of 2021 to study and evaluate replacing the bridges that cross over I-25 in Central Denver. These bridges are near the end of their useful life and are often struck by trucks due to deficient vertical clearance. They are in need of replacement for the safety of all travelers.

This project seeks to:

  • Improve operations and safety for vehicles
  • Improve facilities for bikes and pedestrians

Study Area Map

The study area map shows the bridges over I-25 at 23rd Ave. and at Speer Boulevard and the interchange ramps at both locations are the roadway elements being studied for improvements.
This study area map shows the bridges over I-25 at 23rd Ave. and at Speer Boulevard and the interchange ramps at both locations are the roadway elements being studied for improvements. 

The zoomed out map shows the entire Denver Metro Area and calls out the project area on I-25 near central Denver.
The zoomed out map shows the entire Denver Metro Area and calls out the project area on I-25 near central Denver.

I-25 Central PEL

The I-25: Speer Boulevard and 23rd Avenue Bridge and Interchange Project was identified in the I-25 Central Planning and Environmental Linkages Study (PEL) as a first step for CDOT to improve the transportation infrastructure. Click the link below to learn more about the I-25 Central PEL.

I-25 Central PEL Findings

Other Related Projects & Studies

Several projects and studies have been conducted in the area by the City and County of Denver, CDOT, and other organizations. The project team has reviewed these projects and studies and is developing alternatives that are consistent with them. Review the list of those projects and studies below.

Related Projects & Studies

Ongoing Public Involvement

Throughout the study process, public feedback will be gathered on the alternatives under consideration. The project team has already engaged with several community stakeholder groups, conducted a community survey and distributed informational fliers at a Bike to Work Day event in June of 2023. If there is a stakeholder group we should reach out to, please let us know.

The project team gathered existing-conditions data on transportation infrastructure, vehicle crashes, bike and pedestrian fatalities, and on the height or vertical clearance of the Speer Boulevard and 23rd Avenue bridges over I-25. This information helps to create solutions that improve transportation in this area.


Vehicular Crashes

This section of I-25 (from Colfax Avenue to 20th Street) experiences about 38 percent more crashes and 54 percent more fatal and injury crashes than what would be expected on similar facilities.

Map of total crashes in the project area from April 2015 to March 2020
Map of the existing interchange identifying total crashes from April 2015 to March 2020. Call-outs highlight 217 crashes on southbound I-25 near the Speer Boulevard interchange; 207 crashes on northbound I-25 near the Speer Boulevard interchange; and 216 crashes on northbound I-25 near the 23rd Avenue interchange.

Bike & Pedestrian Facilities

In the existing condition there are no bike or pedestrian facilities on the north side of Speer Boulevard and on the south side of 23rd Avenue. The lack of these facilities leaves connectivity gaps in the bike and pedestrian infrastructure.

Map of existing Bike and Pedestrian Fatalities on Speer Boulevard
Map of the interchange, identifying the existing locations of sidewalks, on-street bike lanes, and multi-use paths in relation to the existing bridge at Speer Boulevard and 23rd Avenue. No sidewalks connect Water Street to the 23rd Avenue bridge and no sidewalks exist on the south side of the 23rd Avenue bridge or the north side of the Speer Boulevard bridge. Legend indicates sidewalks existing along Zuni Street, 15th Street, Platte Street, Water Street, and 23rd Avenue; on-street bike lanes along 23rd Avenue extending to Water Street – terminating at Speer Boulevard; and multi-use paths along both sides of the South Platte River south of Speer Boulevard, along the south side of Speer Boulevard between Platte and Zuni, and south along the adjacent ramps from Zuni to 23rd Avenue.

Minimum Vertical Clearance (Bridge Height over I-25)

CDOT’s standard for bridge height is 16-foot six inches. The clearance for the 23rd Avenue bridge over I-25 ranges from 12 feet, 11 inches at the lowest points to 16 feet, one inch at the highest point.

The clearance for the Speer Boulevard bridge ranges from 12 feet, five inches at the lowest points to 16 feet, nine inches at the highest point.

This photo below shows the Speer Boulevard bridge. The missing concrete and exposed rebar is the result of a truck traveling on I-25 and striking the bridge.

23rd Avenue Bridge with 13 foot 0 inch sign and crew members standing underneath
Speer Boulevard bridge over I-25: The close perspective emphasizes a sign on a bridge pillar displaying a vertical clearance of 13 feet, zero inches which is three and a half feet less than CDOT’s standard vertical clearance.
Speer Boulevard Bridge Cross Section north and southbound I-25 graphic
The graphic depicts the I-25 travel lanes, running northbound and southbound under the Speer Boulevard bridge and depicts warning indicators in the area where the bridge lacks sufficient vertical clearance.
23rd Avenue Bridge Cross Section graphic on north and southbound I-25
The graphic depicts the I-25 travel lanes, running northbound and southbound under the 23rd Avenue bridge and depicts warning indicators in the area where the bridge lacks sufficient vertical clearance.

The project team has begun to collect environmental existing conditions data including residential demographics to identify minority and low income populations, recreational resources, historic properties, and community resources. Navigate the graphics below to access these resources. The project team is also aware that the project is within a City and County of Denver protected view plane.

National Environmental Policy Act (NEPA) analysis

During future National Environmental Policy Act (NEPA) analysis, other existing conditions and potential project impacts will be evaluated for:

  • Air quality and greenhouse gas emissions
  • Water quality
  • Floodplains
  • Waters of the U.S., including wetlands
  • Environmental justice
  • Land use
  • Biological resources (wildlife, fisheries)
  • Threatened, endangered, and state special status species
  • Noxious weeds
  • Hazardous materials
  • Cultural resources (historic and archeological)
  • Paleontological resources
  • Noise
  • Visual resources
  • Recreational resources
  • Secondary and cumulative impacts

Minority and Low Income Populations

Minority and Low Income Populations Map
Map of existing I-25 interchange with West 23rd Avenue and Speer Boulevard intersection depicting census block groups, minority population over 46.10%, and low-income population over 11.02% for the City and County of Denver. Map illustrates areas approximately south of Speer Boulevard overlap with low-income populations, with a minority population identified in the southernmost part of the study area.

Recreational Resources

Recreation Resources Map
Map of the existing I-25 interchange with West 23rd Avenue and Speer Boulevard intersection depicting recreational resources within and surrounding the preliminary study area, including Diamond Hill Path, South Platte River Trail and Cherry Creek Trail that overlap with preliminary study area. Map call outs include (listed starting from northwest of study area to northwest, then west, southwest, south, and east) Highland Park, Viking Park, Ashland Recreation Center, Hirshorn Park, Highland Gateway Park, St. Patrick’s Neighborhood Park, Community Plaza Park, City of Cuernavaca Park, Railyard Dog Park, Denver Skate Park, Commons Park, Confluence Park, Fishback Park, Centennial Park, Speer Boulevard Park, Creekfront Park, Sculpture Park, Downtown Playground, Platte Rover Trail Park, Gates Crescent Park, and Jefferson Park. Highland Gateway Park, Fishback Park, Centennial Park, Confluence Park, Commons Park, Denver Skate Park, Platte River Trail Park, and Gates Crescent Park are located within the preliminary study area

Community Resources and Land Use

Community Resources and Land Use Map
Map of existing I-25 interchange with West 23rd Avenue and Speer Boulevard intersection depicting community resources and land use points of interest; Diamond Hall Promenade west of West 23rd Ave and Speer Boulevard Intersection, Aquarium southwest, Ball Arena South, Empower Field at Mile High southwest. Map calls out preliminary study area of the Project, land use by the City of Denver, recreation/public use of land, agriculture, commercial, industrial, and residential land use and vacant lots and right-of-way.

Historic Resources

Historic Resources Map
Map of existing I-25 interchange with West 23rd Avenue and Speer Boulevard intersection depicting 29 historic resources within the preliminary study area and southeast of the study area along Speer Boulevard.

A Purpose and Need Statement describes what a project is seeking to accomplish and why it is necessary. All potential improvements, including a "No Action" alternative are evaluated against the Purpose and Need, leading to the selection of a "Proposed Action".

Purpose and Need Statement

The purpose of the I-25: Speer Boulevard and 23rd Avenue Bridge and Interchange project is to address the increasing maintenance needs and deteriorating condition of the aging 23rd Avenue and Speer Boulevard bridges over I-25, to provide crossings with adequate vertical clearance over I-25 for interstate travelers, to improve the transportation connection across I-25 for all road users, and to improve the safety issues identified within the interchange complex.

The needs of the project are:

  • Improve safety in the interchange complexes at Speer Boulevard and 23rd Avenue
  • Provide interstate crossings that have adequate clearance over I-25 and structural integrity
  • Accommodate pedestrians, bicycles, and other micro mobility devices (small, low-speed, human- or electric-powered transportation devices) across I-25 and along Speer Boulevard and 23rd Avenue

Alternatives are different conceptual engineering designs that seek to improve the Speer Boulevard and 23rd Avenue bridges and interchanges. A wide range of potential solutions were evaluated and refined to nine draft alternatives, including a No Action alternative.

These alternatives will go through two rounds of evaluation called "alternatives screening". The first round evaluates the alternatives against the Purpose & Need. Any alternative that does not meet the Purpose & Need will not be considered further. In the second round of evaluation, the remaining alternatives will be evaluated against more detailed criteria and compared against each other. The final alternative(s) and the No Action alternative will be carried forward into the NEPA process.

Bike & Pedestrian Facilities

Because of the draft Purpose & Need for this study, all draft alternatives will include bike and pedestrian facilities on both sides of the Speer Boulevard and 23rd Avenue crossings of I-25 to connect to local networks. These facilities will be shown in refinements to the alternatives and included in a future public meeting.

Draft Project Alternatives

The draft alternatives include one No Action alternative, three for 23rd Avenue and five for Speer Boulevard.

Review each of the draft alternatives, noting the design, signalized and unsignalized crossings, safety, and other considerations listed for each alternative. Tell us in the survey if you like each alternative, or not, and why.

No Action Alternative
With the No Action alternative, no improvements would be made other than routine maintenance. This alternative would maintain the existing Speer Boulevard and 23rd Avenue bridges over I-25, and their interchanges with I-25.

Proposed Alternative No Action Map
Map of the existing I-25: Speer Boulevard and 23rd Avenue Bridge interchange. Project area is along Interstate 25 from 23rd Avenue in the south, to 15th Street in the north, and includes the adjacent areas along Speer Boulevard and Water and Platte Streets. Map legend identifies four existing unsignalized pedestrian crossings at the Speer Boulevard ramps – two on either side of I-25; and three at the 23rd Avenue ramps from east of I-25. Map also identifies one existing signalized intersection at the Speer Boulevard ramps to west of I-25, and one at the 23rd Avenue ramps from west of I-25. Additional callouts identify the locations of the existing bridges at Speer Boulevard and 23rd Avenue, crossing over I-25.


23rd Avenue Alternatives

These three alternatives provide adequate vertical clearance for vehicles on l-25 and improve maintenance and structural integrity of the 23rd Avenue bridge over I-25, as well as improve bike and pedestrian connections. Sidewalks will be Installed on both sides of 23rd Avenue in all the alternatives and existing bike facilities will be maintained.

  1. 23rd Avenue Braid Alternative

    A weave occurs when vehicles are both entering and exiting the interstate in the same lane, creating unsafe conditions. A braid eliminates this weave by having exiting and entering traffic cross over or under each other.

    This alternative has northbound vehicles exiting I-25 to go under 23rd Avenue to get to Speer Boulevard. Those who want to get on and off of I-25 to 23rd Avenue will exit on more traditional ramps. This removes the existing weave for drivers going north on I-25 from 23rd Avenue and those trying to get off of I-25 to Speer Boulevard.

    A signal would be added to the east side of the 23rd Avenue bridge to improve non-motorist safety.

     
    Proposed Alternative  23rd Avenue Braid
    Map rendering of the 23rd Avenue Braid Alternative. This alternative demonstrates northbound vehicles exiting I-25 to go under 23rd Avenue to get to Speer Boulevard. This eliminates Speer bound exiting traffic and weaving with northbound I-25 traffic from 23rd Avenue in the same lane. A signalized intersection would be added to the east side of the 23rd Avenue bridge giving two signalized intersections on the 23rd Avenue ramps – one on each side of I-25. Additional call-out identifies the location of the existing bridge at 23rd Avenue crossing over I-25.


  2. Close 23rd Avenue Interchange with I-25 Alternative

    The Close 23rd Avenue Interchange with I-25 Alternative removes the existing ramps to get off and on I-25, so there will not be access to or from I-25 at 23rd Avenue.

    Closing the ramps at 23rd Avenue would eliminate the weave on I-25 between 23rd Avenue and Speer Boulevard. This allows 23rd Avenue to serve bikes and pedestrians.

    Visitors to businesses, such as the Children’s Museum, Aquarium, and REI will need to use Speer Boulevard or other roads. Access to 17th Avenue to, and from, I-25 will still be available.

    Close 23rd Avenue Interchange with I-25 Proposed Alternative
    Map of the Close 23rd Avenue Interchange with I-25 Alternative. This alternative removes the existing ramps between I-25 and 23rd Avenue, eliminating the northbound weave between 23rd Avenue and Speer Boulevard east of I-25. Map also identifies the existing bridge at 23rd Avenue.


  3. 23rd Avenue Bridge Replacement Only Alternative

    The 23rd Avenue Bridge Replacement Only Alternative replaces the bridge and ramps and installs a new signal on the east side at the ramps.

    This alternative does not improve the short northbound I-25 weave between the 23rd Avenue on-ramp and the eastbound Speer Avenue Boulevard off-ramp.

    This alternative provides improved safety for non-motorized users by adding a signal on the east side of the 23rd Avenue bridge. This will improve non-motorist safety by removing the “free-flow” ramp movements.

    Access to and from I-25 from 23rd Avenue would remain.

    Proposed Alternative of 23rd Avenue Bridge Replacement Only Map
    Map of the 23rd Avenue, Bridge Only, Alternative. This alternative replaces the bridge and ramps on the east side of I-25 at 23rd Avenue; however, the northbound Speer Boulevard offramp traffic would still merge with 23rd Avenue traffic accessing northbound I-25. A signalized intersection would be added to the east side of the 23rd Avenue bridge giving two signalized intersections on the 23rd Avenue ramps  one on each side of I-25. Additional call-out identifies the location of the existing bridge at 23rd Avenue crossing over I-25.

Speer Boulevard Alternatives

The five Speer Boulevard alternatives provide adequate vertical clearance for vehicles on I-25 and improve maintenance/structural integrity of the Speer Boulevard bridges over I-25, as well as improve pedestrian, bicycle, and non-motorist connections. Bike and Pedestrian facilities will be installed on both sides of Speer Boulevard, in all the alternatives. Also, all Speer Boulevard alternatives remove the weave between the I-25 northbound on- and off-ramps, improving safety for vehicles on I-25.

  1. Speer Boulevard Bridges Replacement Only Alternative

    The Speer Boulevard Bridges Replacement Only alternative would increase the vertical clearance over I-25 with new bridges and ramps that have the same layout as what exists today.

    The loop ramp in the northeast corner of the interchange will be removed to eliminate the existing weave for those getting on and off I-25 at Speer Boulevard, in the northbound direction. In this alternative, northbound I-25 traffic exiting westbound Speer Boulevard would exit before the Speer Boulevard bridge and make a left-turn at the top of the ramp where there will be a new traffic signal.

    This alternative would improve bike and pedestrian safety by adding a traffic signal on the east side of the interchange. A traffic signal will provide a pedestrian signal for bikes and pedestrians. This allows for a protected crossing of the ramps for bikes and pedestrians.

     
    Proposed Alternative Speer Boulevard Bridges Replacement Only
    Map of the Speer Boulevard, Bridges Only, Alternative. This alternative would have the same ramp layout that is currently in-place except that the loop ramp in the northeast corner of the interchange would be removed to eliminate the existing weave for vehicles entering and exiting I-25 at Speer Boulevard in the northbound direction. I-25 traffic exiting to access westbound Speer Boulevard would exit before the Speer Boulevard bridge and make a left-turn at the top of the ramp where a new signalized intersection would be added, giving two signalized intersections on the 23rd Avenue ramps; one on each side of I-25. Additional call-out identifies the location of the existing bridge at 23rd Avenue crossing over I-25.


  2. Speer Boulevard Single-Point Urban Interchange with I-25 Alternative

    The Speer Boulevard Single-Point Urban Interchange with I-25 alternative has a single traffic signal in the middle of the bridge. The left turns all occur at that single traffic signal, while right turns are more traditional to get on and off of I-25.

    This alternative provides improved vehicular operations by having the traffic go through one signal.

    This alternative would improve bike and pedestrian safety by adding a traffic signal to the Speer Boulevard bridge. A traffic signal will provide a pedestrian signal for bikes and pedestrians. This allows for a protected crossing of the ramps for bikes and pedestrians.

     
    Proposed Alternative Speer Boulevard Single-Point Urban Interchange with I-25
    Map of the Speer Boulevard, Single-Point Interchange with I-25 Alternative. This alternative has a single traffic signal in the middle of the bridge, with all left turns occurring at this location. North and southbound traffic exiting I-25 would flow either to Speer Boulevard east or west. East and westbound Speer Boulevard traffic can access ramps to I-25 north or south or continue on Speer. Map identifies one signalized intersection at the existing bridge at Speer Boulevard crossing over I-25.


  3. Speer Boulevard Diamond Interchange with I-25 Alternative

    The Speer Boulevard Diamond Interchange with I-25 alternative is a traditional interchange type with I-25 where left and right turns occur at a new traffic signal at both ends of the bridge.

    This alternative improves bike and pedestrian safety by adding a traffic signal on the east side of the interchange and a more traditional interchange for motorists.

     
    Proposed Interchange Speer Boulevard Diamond Interchange with I-25
    Map of the Speer Boulevard Interchange with I-25 Alternative. This alternative is a traditional diamond interchange, where left and right turns occur at a new traffic signal at both ends of the bridge. Map identifies two signalized intersections at the Speer Boulevard ramps, one on each side of I-25 and the location of the existing bridge at Speer Boulevard crossing over I-25.


  4. Speer Boulevard Partial Clover Leaf Interchange with I-25 Alternative

    The Speer Boulevard Partial Clover Leaf Interchange with I-25 alternative operates like a traditional interchange with ramps starting and ending at traffic signals at each end of the Speer Boulevard bridge.

    For those traveling south on I-25 to go east or west on Speer Boulevard, drivers will use a loop ramp in the southwest corner.

    This alternative improves bike and pedestrian safety by adding a traffic signal on the east side of the interchange. Bikes and pedestrians would need to cross multiple lanes of traffic in the southwest corner of the interchange


    Proposed Alternative Speer Boulevard Partial Clover Leaf Interchange with I-25
    Map of the Speer Boulevard Partial Clover Leaf Interchange with I-25 Alternative. This alternative operates like a traditional diamond interchange, where left and right turns occur at a new traffic signal at both ends of the bridge, except for the southbound I-25 exiting traffic. Vehicles traveling south on I-25 to access Speer Boulevard, either east or west, would continue under the Speer Boulevard bridge and then use a cloverleaf loop ramp in the southwest corner of the interchange. Map identifies two signalized intersections at the Speer Boulevard ramps, one on each side of I-25 and the location of the existing bridge at Speer Boulevard crossing over I-25.


  5. Speer Boulevard Diverging Diamond Interchange with I-25 Alternative

    In the Speer Boulevard Diverging Diamond alternative, eastbound and westbound traffic on Speer Boulevard will “cross over” each other to travel across the bridge on the left-side of the road (opposite the normal right-side driving). The cross over will occur at both sides of the bridge at traffic signals. An example of this can be found at U.S. 36 and McCaslin Boulevard.

    This design eliminates the need for traditional left-turns at the traffic signals, which improves vehicle operations and safety.

    This option could allow for separated bike and pedestrian facilities through the center of the bridge and would improve bike and pedestrian safety by removing left turn conflicts with traveling vehicles


    Proposed Alternative Speer Boulevard Diverging Diamond Interchange with I-25
    Map of the Speer Boulevard Diverging Diamond Interchange with I-25 Alternative. This alternative shows eastbound and westbound traffic on Speer Boulevard “cross over” each other to travel across the bridge on the left side of the road. The cross-over will occur at both sides of the bridge at traffic signals. The crossing allows for vehicles to turn left on and off freeway ramps more efficiently without stopping or crossing opposing lanes of traffic. Map identifies two signalized intersections at the Speer Boulevard ramps, one on each side of I-25 and the location of the existing bridge at Speer Boulevard crossing over I-25.

Alternative Development and Screening

In this current phase, we create design options to address the Purpose and Need. The project will evaluate these alternatives against screening criteria.

NEPA Analysis

NEPA requires that projects using federal funds, requiring a federal permit or linked to a federal action analyze effects on the natural and social environment. Since CDOT is using federal funding for this project, once a recommended alternative(s), including the No Action, are selected, the project will go through NEPA review and documentation.

The public involvement process shall continue during NEPA. CDOT and FHWA will select an alternative at the conclusion of the NEPA process. The document will also disclose impacts, necessary permits, and mitigation of those impacts for the selected alternative.

The project will undergo CDOT's Procedural Directive 1601 Process for Interchange Improvements following NEPA and before final design. Following this process, final engineering design, potential right of way acquisition, and construction could occur if a Build Alternative is selected.

The area around the Speer Boulevard and 23rd Avenue Bridge and Interchange Project is undergoing changes, including Empower Field at Mile High Stadium, Ball Arena, Elitch Gardens, Speer Boulevard, and along the South Platte River. The project is taking these developments into consideration during the evaluation of alternatives and the future NEPA process.

  • River Mile: Rive Mile is a mixed-use development connecting the urban environment to the natural environment. River Mile will incorporate residential, commercial, and business development to create a “new kind of downtown” experience in Denver.
  • KSE Ball Arena Vision Plan: KSE Ball Arena Vision Plan is a mixed-use neighborhood made accessible to the entire city, including plans to offer improved connections across Speer Boulevard, Auraria Parkway, and the Light Rail line. The emphasis is on multimodal transportation and livable streets.
  • Diamond Hill Redevelopment: The Diamond Hill Redevelopment is a 10.5-acres site for mixed-used development. One-thousand residential units and two office buildings are proposed and will allow up to 12 stories.
  • Cherry Creek & Speer Boulevard Vision Study: The Cherry Creek and Speer Boulevard Vision Study will improve how people move through Speer Boulevard and Cherry Creek Trail between Colfax Avenue and I-25. The study focuses on environmental, public space, and recreational, cultural, connectivity, inclusivity ,commerce and education elements. The study builds off the Urban Land Institute Technical Advisory Panel Report.

Finalizing Purpose & Need

The team will review any public input received and finalize the Purpose & Need Statement.

Screening and Refining Alternatives

The project team will combine technical evaluation and community input to screen out draft alternatives that do not sufficiently meet Purpose & Need and refine the remaining alternatives for more detailed evaluation.

Next Public Meeting

Another public meeting is planned for the summer of 2024. That public meeting will:

  • Show alternative(s) that are recommended to advance into NEPA, based on technical and public input
  • Show bike and pedestrian facilities for recommended alternative(s)
  • Show bike and pedestrian facilities for recommended alternative(s)

Thank You!

Thank you for your time and interest in the Speer Boulevard & 23rd Avenue Bridge and Interchange Project. Please provide your input at the link below no later than April 22, 2024.

April 2024 Open House & Public Involvement Survey