Holman Highway 68 Roundabout
Location
17 Mile Drive/Holman Highway 68/Highway 1
City or County Responsible for Project
City of Monterey
Category
Roads: Efficient and Sustainable Road Maintenance, Construction and Reconstruction Projects.
Author
Andrea Renny, PE, PTOE
City of Monterey
580 Pacific Street – Monterey, CA 93940
(831) 646-3705
Project Description
The Holman Highway 68 Roundabout was designed to relieve congestion at the busy intersection of Holman Highway 68, southbound Highway 1 ramps, and 17 Mile Drive near the entrance to Pebble Beach and the area’s only Community Hospital. The selected improvements featured two closely spaced roundabouts, one of which is a “teardrop” roundabout located at the access point to 17 Mile Drive. The roundabout solution addressed all of the unique characteristics of the area including congestion mitigation leading to reduced vehicle idling times and Greenhouse Gas Emissions due to eliminating traffic signals and stop signs. It improved response times and access to the Community Hospital and local Fire Department, as well as protection of the existing surrounding Monterey Forest; enhancement to the existing scenic corridor; and improved access for all users with a small footprint. The project was one of the first in the state to use the Intersection Control Evaluation (ICE) process, which was adopted by Caltrans in August 2013, to help evaluate and identify the best solution for intersection control for intersections located in the State right of way. The ICE process clearly demonstrated the safety and operational performance advantages of roundabout control over signal control by providing the framework for a side-by-side comparison. The ICE process also established a streamlined Caltrans approval process and approach to consensus building. The ICE performance measure matrix made it easier to educate policy makers and the public on the roundabout as the key component of an unprecedented solution, leading to broad local support and full project funding. A project video of the Roundabout ribbon cutting ceremony where City and County staff and residents speak regarding the broad public support for the project is located at https://www.youtube.com/watch?v=50sFiqRrQqc . The designers maximized roundabout design principles to redefine current engineering thinking thus leveraging the greater capacity of the roundabouts to minimize upstream and downstream roadway improvements; ultimately replacing a previously approved widening project of State Route 68 including bridge replacement and signalized intersection, estimated at $21 million. The project was advertised for bidding in late 2015, with Granite Construction as the low bidder at $6.3 million. Total project costs were approximately $10.7 million, which represents a substantial savings over the previously approved traffic signal and road widening project. The Holman Highway Roundabout Project supports the League’s and CSAC’s priorities and goals by demonstrating the cost effectiveness of roundabouts as a high capacity intersection solution that save both current capital construction funds and future maintenance costs as compared to traditional signalized intersections. Thus, further implementation of this type of project would further stretch already limited transportation funding.
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