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Highway 119 Bikeway Project

The Diagonal Highway 119 Bikeway Design Project

CO 119 Diagonal Highway Transportation Projects Community Meeting, June 27, 2022

Boulder County’s Community Planning & Permitting Department, the Colorado Department of Transportation (CDOT), and the Regional Transportation District (RTD) hosted a community meeting on June 27, 2022 on the dual transportation projects currently being designed for Colorado Highway 119 between Boulder and Longmont (The Diagonal Highway). The featured projects include the CO 119 Commuter Bikeway Design Project (Boulder County) and the CO 119 Safety and Mobility Project (CDOT and RTD). The meeting included a presentation by project team members on design plans and an overview of how the two projects work together to improve safety and enhance multimodal connectivity on the corridor.

CO 119 Bikeway and Safety and Mobility Project Comment Form

View the video of the June 27th Public Meeting below. Q&A section starts at 46 minutes.

View the presentation slides

This video shows the proposed alignment of the nine-mile CO 119 Commuter Bikeway, including how the bikeway will connect to bus station areas and adjacent roadways. The proposed bikeway curves to avoid wetlands, irrigation infrastructure, and other obstacles. Bikeway underpasses are shown in brown.

Preliminary Design

The June 27th public meeting showed the draft Preliminary design for the bikeway and the bikeway underpasses, bridges, and at-grade crossings and how the bikeway would connect to the bus rapid transit stations.

Preliminary design also includes:

  • A more in-depth study of the constraints and design issues that will help determine the best alignment for the bikeway.
  • Map of above ground and underground utilities, trees, culverts, and irrigation ditches. This will show what needs to be moved, redesigned or worked around.
  • Soil sampling and groundwater measurements. This is important so the bikeway won’t sink, or buckle and underpasses won’t flood.
  • If threatened or endangered wildlife species live or migrate through project area.


The foundation for Preliminary design was the CO 119 Bikeway Design Validation memo and comments from the public and the adjacent city’s transportation staff.

The CO 119 Bikeway Design Validation Memo was a refinement of the Conceptual Design.

A new approach to outreach: The county knows that the best bikeway is designed to accommodate many different types of people. We have broadened the way we do outreach so we can receive comments and feedback from a larger diversity of voices. To strive for this broader outreach, we have met with bicycle and mobility advocacy organizations and businesses along the corridor. We have added Spanish interpretation to our virtual public meetings and are making a concerted effort to provide written materials in Spanish. We have also created two advisory committees.

Community Advisory Committee

Transportation inclusive planning group

Community Advisory Committee members were chosen via an application process. The seats represented on the committee are:

  1. Community member who resides or works in or near Longmont
  2. Community member who resides or works in or near Boulder
  3. Community member who resides or works in or near Niwot or Gunbarrel
  4. Business owner on or near the corridor that employs workers with transportation challenges
  5. Employee on or near the corridor who has transportation challenges commuting to work
  6. Cyclist who uses or crosses the corridor as part of their regular bike commute route
  7. Recreational cyclist
  8. Current public transit user along the corridor
  9. Person with mobility challenges
  10. Liaison from Spanish language Equity Committee

Spanish Language Equity Committee

The Spanish Language Equity Committee is made up of 8 members from the County’s Spanish speaking community and was created to help the county’s outreach efforts reach our Spanish speaking residents.

Summary of Public Input in 2021

During the first phase of the CO 119 Bikeway Design Project in Summer/Fall 2021, the public provided questions and comments covering an array of topics through the Public Meeting on August 30th, online comment forms, and public surveys. This document summarizes this input alongside commentary and responses from the Project Team.

Boulder County is working closely with CDOT, RTD, the Cities of Boulder and Longmont and Commuting Solutions so the bikeway and the Mobility Project and the PEL for CO 52 work seamlessly together for all travelers.

Map of SH 119 Bikeway Project's coordination with other projects along the main line of the SH 119 corridor

The Concept Plan, which was funded by CDOT, was completed in 2019. The Concept plan included the first draft of an alignment for the Bikeway. Once the County secured funding through a Denver Regional Council of Governments grant, the plan was presented to the public via a video public meeting. The public shared thoughts, concerns, and ideas during the meeting, through comment forms and through an online survey. These comments are being incorporated into the next step in the design process.

In 2014, The Northwest Area Mobility Study (NAMS) was completed. The NAMS report includes a prioritized list of mobility improvements for the Northwest area of the Regional Transportation District’s (RTD) service area. CO 119 was identified as the top priority corridor for improving mobility in Boulder County and included recommendations for Bus Rapid Transit and a separated bike facility.

This collaborative effort included RTD, the Colorado Department of Transportation (CDOT), the Denver Regional Council of Governments (DRCOG) and the Northwest Area Stakeholders: 36 Commuting Solutions, City of Arvada, City of Boulder, Boulder County, City and County of Broomfield, City of Lafayette, City of Longmont, City of Louisville, North Area Transportation Alliance (NATA), Town of Superior, University of Colorado, and City of Westminster.

In 2019, a Planning and Environmental Linkages (PEL) report was completed which identified the multi-modal corridor vision for CO 119. This vision includes:

  • Bus Rapid Transit (including Park-n-Rides, new stations, Business and Transit lanes, Transit Signal Priority/queue jump lanes)
  • Intersection Improvements
  • BRT/Managed Lanes
  • Separated Bikeway

For more information please go to the Commuting Solutions website.

Board of County Commissioners (BOCC) Town Hall Webinar on the Diagonal Highway 119 Makeover, April 14, 2022

Boulder County residents were invited to join the Board of County Commissioners for a Town Hall meeting about the Highway 119 (Diagonal) Makeover. After a presentation by staff from the Transportation Planning Unit of Boulder County Community Planning & Permitting, attendees were encouraged to ask questions in the Q&A feature of Zoom about the project. Commissioners also fielded public comments on general transportation issues.

Virtual meeting on the CO 119 (the Diagonal) Bikeway Design, August 30, 2021

Boulder County’s Community Planning & Permitting Department and CDOT invited the public to a virtual meeting presentation on the CO Highway 119 Bikeway Project on August 30, 2021. Staff discussed the conceptual design of the bikeway and potential connections at the north and south ends of the project. Participants had an opportunity to ask questions and provide feedback on the design concepts at the meeting.

Safety & Comfort

What are the County’s plans for ensuring that the CO 119 Bikeway is safe and comfortable for all types of users?

The County is committed to “Vision Zero,” the idea that even a single traffic death is one too many. Based on this principle, the CO 119 Bikeway design and concept development prioritizes safety as a paramount consideration. Multiple design approaches will be evaluated for each at-grade crossing. The evaluation will consider variables like traffic volumes, traffic speeds, light distance, length and type of crossing and available right-of-way.

How is the Project Team planning to address lighting, air quality, and noise?

The Project Team will consider issues related to lighting, air quality, and noise within the parameters of the project.

  • The current plans call for lighting at underpasses, bridge locations, trail connections, and BRT station access at 63rd St., and Niwot Road.
  • Currently, there are no plans for a “green buffer” (e.g., trees to block sound and fumes), but the project team will continue to explore options to mitigate sound and air quality concerns.
  • CDOT is conducting a noise study as a part of the CO 119 Mobility project. Results are not available at this time.

Construction & Cost

What is the timing of construction?

Construction will be dependent on funding; the project may be built in phases. The county is working closely with CDOT and RTD on a “touch once” approach so that one area of the road and bikeway are under construction simultaneously and only once, pending funding availability.

What is the current cost and budget for the Project?’

The project funding is broken up into two parts: (1) Planning and (2) Construction. The Conceptual Plan was funded by the Colorado Department of Transportation (CDOT). The preliminary and final design is fully funded through a Denver Regional Council of Governments (DRCOG) plus funds from the county. The design is expected to cost approximately $2.5 million. Construction for the project is not yet funded and is estimated to cost $30- 35 million. The county is looking at every possible funding source for the construction funds.


What is the maintenance approach for the bikeway, particularly given Colorado’s winter weather patterns? This includes snow and ice removal, and flooding at underpasses.

The Project Team is planning for ice, snow, and excess precipitation in a number of ways:

  • Considering the use of a crown or slope and curb and gutter similar to the way roads are constructed so snowmelt and rain can drain quickly.
  • Snow removal on the bikeway will likely follow similar protocols as the US 36 Bikeway, which is plowed after 1 inch of snow and before 7:00am
  • Drainage at each underpass will be evaluated and the bikeway will be designed so that each underpass will be able to drain small storm events.

Design Elements & Specific Locations

What are the expected design specifications for the Bikeway?

The bikeway is still in the initial design phase. However, there are some design assumptions and specifications:

  • The Project Team is planning for a variety of bikeway users with large speed differentials. There are design concepts for either a widened bikeway or a “casual zone” in high-activity areas (see the Typical Cross Section Concept image below).
  • The bikeway width will vary along the corridor with a typical width of 12′ and wider widths in high activity areas.
  • The surface will be concrete.
  • Underpass size will vary between 16′ wide x 10 feet tall and 16’ wide by 8’ tall depending on project constraints.

What information is available about specific locations along the proposed route(s) or in their vicinity?

  • Underpasses: Underpasses have been identified at the following intersections: Jay Road, 63rd Street, State Highway 52, Niwot Road, and Airport Road.
  • LoBo Trail: Improvements to the LoBo trail are outside the scope of this project. The Lobo Trail is a separate project and will not be deprioritized in favor of the 119 Bikeway.
  • Transit Station Parking: There will be transit station parking at Niwot Road, Colorado Highway 52 and 63rd Street. These parking areas will also be used as trailhead access parking.
graphic showing proposed width options for CO 119 bike path


¿Cuáles son los planes del condado para garantizar que ciclopista CO 119 sea segura y cómoda para todo tipo de usuarios?

El Condado está comprometido con la Visión Cero , la idea de que tan solo una muerte por tránsito ya sería demasiado. En base a este principio, el diseño y el desarrollo del concepto de la ciclopista CO 119 prioriza la seguridad como una consideración primordial. Se evaluarán múltiples enfoques de diseño a nivel por cada cruce. La evaluación considerará variables como el volumen de tráfico, la velocidad del tráfico, la distancia, la longitud y el tipo de cruce, y el derecho de paso disponible.

¿Cómo planea el equipo del proyecto abordar la iluminación, la calidad del aire y el ruido?

El equipo del proyecto considerará cuestiones relacionadas con la iluminación, la calidad del aire y el ruido dentro de los parámetros del proyecto.

  • Los planes actuales requieren iluminación en pasos subterráneos, en los puentes, conexiones de senderos y acceso a la estación BRT en la calle 63 y Niwot Road.
  • Actualmente, no hay planes para un “amortiguador verde” (por ejemplo, árboles para bloquear el sonido y el humo), pero el equipo del proyecto continuará explorando opciones para mitigar los problemas de sonido y calidad del aire.
  • El CDOT está llevando a cabo un estudio de ruido como parte del proyecto de movilidad CO 119. Los resultados no están disponibles en este momento.


¿Cuándo será el momento de la construcción?

La construcción dependerá del financiamiento, el proyecto se puede construir en fases. El condado está trabajando en estrecha colaboración con el CDOT y RTD en un enfoque de “tocar una sola vez” para que un área de la carretera y la ciclopista se construyan simultáneamente, y de una sola vez, en espera de la disponibilidad de fondos.

¿Cuál es el costo y el presupuesto actual del proyecto?

El financiamiento del proyecto se divide en dos partes: (1) Planificación y (2) Construcción. El Plan Conceptual fue financiado por el Departamento de Transporte de Colorado (CDOT). El diseño preliminar y final está totalmente financiado a través de un Consejo Regional de Gobiernos de Denver (DRCOG), además de fondos del condado. Se espera que el diseño cueste aproximadamente $ 2.5 millones. La construcción del proyecto aún no está financiada y se estima que costará entre $ 30 y 35 millones. El condado está buscando todas las fuentes de financiación posibles para los fondos de construcción.


¿Cuál es el enfoque de mantenimiento para la ciclopista, particularmente dados los patrones de clima invernal de Colorado? Esto incluye la remoción de nieve y hielo, e inundaciones en pasos subterráneos.

El equipo del proyecto está planificando el hielo, la nieve y el exceso de precipitación de varias maneras:

  • Considerando el uso de una corona o pendiente, un bordillo y una cuneta similar a la forma en que se construyen las carreteras, de modo que el deshielo y la lluvia puedan drenar rápidamente.
  • La remoción de nieve en ciclopista probablemente seguirá protocolos similares a los de la ciclopista US 36, que se remueve después de 1 pulgada de nieve y antes de las 7:00 a.m.
  • Se evaluará el drenaje en cada paso subterráneo y la ciclopista se diseñará de modo que cada paso subterráneo pueda drenar pequeños eventos de tormenta.


¿Cuáles son las especificaciones de diseño esperadas para la ciclopista?

La ciclopista se encuentra todavía en la fase de diseño inicial. Sin embargo, existen algunas suposiciones y especificaciones de diseño:

  • El equipo del proyecto está planificando para una variedad de usuarios de ciclopista con grandes diferenciales de velocidad. Existen conceptos de diseño para una ciclopista ampliada o una “zona informal” en áreas de alta actividad (consulte la imagen del concepto de sección transversal típica a continuación).
  • El ancho de la vía para bicicletas variará a lo largo del corredor con un ancho típico de 12 ‘y anchos más anchos en áreas de alta actividad.
  • La superficie será de hormigón.
  • El tamaño del paso subterráneo variará entre 16 ‘de ancho x 10 pies de alto y 16’ de ancho por 8 ‘de alto dependiendo de las limitaciones del proyecto.

¿Qué información está disponible sobre ubicaciones específicas, a lo largo de la (s) ruta (s) propuesta (s) o en sus alrededores?

  • Pasos inferiores: Se han identificado pasos inferiores en las siguientes intersecciones: Jay Road, la calle 63, Carretera estatal 52, Niwot Road y Airport Road.
  • Sendero LoBo: Las mejoras al sendero LoBo están fuera del alcance de este proyecto. El Lobo Trail es un proyecto separado y no se perderá prioridad en favor de la ciclopista CO 119.
  • Estacionamiento en la estación de tránsito: Habrá estacionamiento en la estación de tránsito en Niwot Road, Colorado Highway 52 y 63rd Street. Estas áreas de estacionamiento también se utilizarán como estacionamiento de acceso al comienzo del sendero.

Concepto típico de sección transversal

graphic showing proposed width options for CO 119 bike path


Boulder County, CDOT, and RTD submitted an application for $25M to the USDOT for a Rebuilding American Infrastructure with Sustainability and Equity (RAISE) grant. This funding would enable CDOT and RTD to construct additional multimodal improvements on the CO 119 Diagonal Highway not currently programmed for implementation through the CO 119 Safety and Mobility Project or other active projects on the corridor. Of the $124M needed for the entire project, 90% (or $99M) has already been acquired. The RAISE grant would provide the remaining funding piece necessary to implement this critical infrastructure project.

Project Coordinator

Boulder County Community Planning & Permitting
Stacey Proctor, 303-441-1107

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