Department staff and the County’s engineering consultant have studied options to improve the major intersections with CR 98 and have engaged the community to discover concerns about the corridor and the proposed alternatives. The studies conclude that roundabouts provide the safest alternative for all vehicles and the design can provide access for all the varied users of the corridor. Board concurrence is desired before proceeding with design and environmental.
BACKGROUND
The CR 98 Phase II project will extend the improvements completed in 2014 between Woodland and County Road 29 southward to the Solano County line. The project will add eight foot paved shoulders, twelve-foot unpaved clear recovery zones, and remove obstacles such as ditches and power poles away from the edge of the road. This corridor carries a wide range of vehicles including commuters, bicycles including both recreational and commuting, farm to market trucking, aggregate products trucking, and a wide range of farm vehicles. Alternatives for improvements at the intersections of CR 98 with CR 31, CR 32 (Russell Boulevard) and Hutchison Drive include traffic signals with left-turn lanes and roundabouts.
The project received federal transportation funding for preliminary engineering and project development through the Sacramento Council of Governments (SACOG) in the amount of $1,593,400. Funding for right of way acquisition is in the SACOG staff recommendation for approval by the SACOG Board in December 2018.
The County retained GHD (formerly Omni-Means, Inc.) to evaluate the feasibility of the proposed intersection types, prepare preliminary layouts for both roundabouts and signals, assist in public engagement and property owner meetings, and prepare the design for the intersection alternative selected.
GHD prepared an Intersection Control Evaluation (ICE) Report for all three intersections. The ICE Report compares the life cycle costs over twenty years of the roundabout and signal alternatives for each of the three major intersections. It is the national standard for intersection evaluation. The cost factors considered were safety (collisions), construction, operation and maintenance, fuel, greenhouse gas, and delay. The ICE Report concluded that a roundabout has a significantly lower life cycle cost than a signal at all three intersections. The primary factor in the lower life cycle costs for roundabouts is the cost of collisions. The roundabout has only 8 potential locations for vehicle collisions compared with 32 for signals (all way stops as well). Also, roundabouts, through a series of curves, require every vehicle to slow down approaching and entering the intersection so collisions tend to be less severe compared with signals which require the intention of the driver to slow down. A summary of the life cycle costs is shown below:
| CR 98 Intersection Life-Cycle Costs |
| Intersection |
Hutchison |
Russell (CR 32) |
CR 31 |
| |
Signal |
Roundabout |
Signal |
Roundabout |
Signal |
Roundabout |
| Collision Costs |
$ 8,800,000 |
$ 681,000 |
$ 8,976,000 |
$ 681,000 |
$11,828,000 |
$ 2,864,000 |
| Total Life-Cycle Costs |
$12,637,000 |
$4,182,000 |
$14,276,000 |
$5,193,000 |
$17,980,000 |
$7,293,000 |
A typical concern regarding roundabouts is the ability of large vehicles to navigate the intersection. The preliminary layouts are designed to handle the California Legal Design Vehicle, which is a truck-semitrailer combination with a maximum overall length of 65’ and a 60’ minimum turning radius, as well as large farm equipment. A Triplane Grader, (40 feet long by 16’ wide) pulled with a John Deere Tractor (15.6’ long) was analyzed through the proposed roundabouts. This combination vehicle is able to negotiate the turns with minimum overhang over the curb returns. Any additional farm equipment, that farmers have concerns about, will be analyzed in the detailed design phase.
On April 2, 2015, Supervisor Chamberlain was kind enough to allow Caltrans to stake (mark on the ground) the exact footprint of the roundabout proposed at the intersection of CR 89 with State Highway 16 in one of his fields. Local farmers used an array of on-road and off-road farm equipment to verify the ease and safety of travel using the equipment in a typical roundabout. Specifically the types of vehicles included a maintenance truck with a trailer, a hay truck with double trailers, a harvester, and a John Deere Tractor with a sixteen-foot wide leveler. A video of the safe travel of the equipment is available on the CR 98 Project website locatedhere.
Fire trucks and other first responders will have the ability to maneuver around vehicles that don’t clear the intersection by the use of mountable curbs, if necessary. Bicyclists will have the option of riding through the intersection like a motorized vehicle or taking a path off the road and crossing the road as a pedestrian. The advantage of roundabouts is that pedestrians will only need to cross one lane of traffic at a time with a median refuge to wait in to cross the second lane of traffic.
In a preliminary review of the right of way needs for both alternatives, the right of way requirements for the three roundabouts is approximately one-half of an acre less than for a signal at all three locations.
Because of the improved safety with roundabouts and the ability of all vehicles to use it, staff recommends that the County proceed with design and environmental for roundabouts at the intersections of CR 98 with Hutchison Drive, Russell Boulevard, and CR 31. |
Staff held four public meetings to present information about the project and collect concerns about the corridor and feedback about project proposals starting on March 2, 2016 with the last one on October 17, 2018. GHD participated in three of these meetings. The initial meetings generally shared and collected information about the existing road, proposed design for the road, and the types of intersections under consideration (signal or roundabout). The later meetings focused on proposed layouts for the intersections, pros and cons for each type of intersection, and finally staff’s recommendation to construct roundabouts at the major intersections within the project.
Staff also met with property owners at eleven of the twelve corners of the intersections to go over in detail the intersection alternatives and how they would affect their property. The one group of owners that we didn’t meet with did not feel a need to see the plans. As a result of these meetings, the preliminary design has been modified to the extent possible to address property owners concerns.
Staff presented the project and intersection information to the Board’s Transportation Advisory Committee (TAC). The TAC unanimously endorsed the recommendation to construct roundabouts.
On November 1, 2018, staff presented the project and intersection information to the West Plainfield Fire Commission and provided information on the impact of roundabouts on road safety and first responders. On November 20, 2018, the West Plainfield Fire Commission discussed the project at their commission meeting and decided not to take a position on the construction of roundabouts on the CR 98 corridor.
University of California, Davis has been collaborating throughout the project development to date and will continue to be a partner and funder based on the Agreement approved by the Board of Supervisors on September 25, 2018.
Staff has reached out to the Farm Bureau as well as fire officials with the City of Davis and the University of California at Davis to schedule meetings to review the project with them. A meeting with the City of Davis fire has been scheduled for December 4, 2018.
As design and environmental proceed, property owners, stake holders such as farm and first responder partners, and the general public will continue to be engaged.
A document with every comment received on the project through November 23rd and a table showing staff response to comments are attached. |