State Highway 119

About State Highway 119

State Highway 119, locally known as the Diagonal, connects Boulder to Longmont and travels through Gunbarrel and Niwot. Currently there are 45,000 vehicles a day that travel along the corridor. There is a projected 25% increase in traffic by the year 2040. To address growing travel demand and provide improved mobility in the northwest region, RTD, along with the Northwest Mayors & Commissioners Coalition, completed the Northwest Area Mobility Study (NAMS) in 2014. The study determined a prioritized list of mobility improvements for the region. Implementing Bus Rapid Transit (BRT) along SH 119 was identified as a high-priority project.

State Highway 119 currently has 1,500 transit riders a day with a likely increase of 33% with the proposed multimodal improvements such as Bus Rapid Transit and express lane usage.

First and Final Mile Study

A consultant team led by Fehr & Peers will conduct a planning study to create corridor-wide recommendations for bicycle and pedestrian connections, shared parking, and microtransit.

This study will develop a plan to increase transit ridership by developing strategies to improve multi-modal connectivity and safety to the future Bus Rapid Transit stations along the corridor.

Feasibility Studies and Results

In 2019, RTD completed studies to determine the feasibility of implementing Bus Rapid Transit along State Highway 119. At the same time, CDOT completed a Bikeway Study that resulted in preliminary bikeway concepts. During this process, RTD gathered public input through open houses, online comments and surveys. As a result of these studies, three alternatives were proposed for BRT on the corridor: bus on the outside shoulder, bypass lanes/queue jumps and signal priority, and an inside managed lane.


SH 119 Corridor Projects and Timeline
Solicitation for SH 119 Bikeway Design
SH 119 First and Final Mile Kick Off Meeting Presentation 2020
SH 119 One Pager 2020
US 36 Mayors & Commissioners Coalition Fact Sheet 2019
State Highway 119 Bus Rapid Transit (BRT) Corridor Project Update
SH 119 Corridor Vision
SH 119 Corridor Improvements
SH 119 PEL Funding Plan
SH 119 PEL Questionnaire
State Highway 119 Multi-Modal Planning and Environmental Linkage Study Report Part 1
State Highway 119 Multi-Modal Planning and Environmental Linkage Study Report Part 2
State Highway 119 Multi-Modal Planning and Environmental Linkage Study Report Part 3
State Highway 119 Multi-Modal Planning and Environmental Linkage Study Report Part 4

Rendering of the proposed future SH 119 corridor:

The preferred option is to implement BRT using managed lanes. BRT and managed lanes will provide:

  • Highest travel time savings: 37-minute travel time (29 minutes saved in comparison to the BOLT)
  • Best transit service reliability
  • Higher transit ridership
  • Greatest number of travel options and benefits for all users: vehicles, transit, carpool, express tolls, and bicyclists while reducing congestion. 7,620 – 7,640 people traveling through the corridor per day – a 33% increase compared to the existing corridor
  • Improvements can be phased over time as funding becomes available

Project Cost and Funding

The project is estimated to cost $253.3 million. Currently, $93 million in funding has been secured for project elements such as BRT service/branding, station enhancements, stations, Coffman Street busway, Business Access and Transit (BAT) lanes and bus queue jump lanes at State Highway 52.