Segment 4E North is the seventh and final mainline segment of the Highway 101 Carpinteria to Santa Barbara program, an approximately 10.9-mile reconstruction being delivered by Caltrans/SBCAG and Granite Construction using Construction Manager/General Contractor, or CM/GC, project delivery. Granite was selected as CM/GC in December 2018, with construction on the first segment beginning in 2020. Approximately 75% of the corridor was complete in 2026, with overall completion projected for late 2028.
The crew uses a Cat 336 Excavator for the Retaining Wall 117 excavation.
The scale is substantial: 67 lane-miles of concrete pavement and another 44 shoulder lane-miles, involving approximately 200,000 cubic yards of concrete. All mainline lanes and shoulders are being constructed with continuously reinforced concrete pavement (CRCP), while jointed plain concrete pavement (JPCP) has been used on several ramps. More than 350,000 tons of existing roadway and structures are being recycled for reuse as base and structural backfill.
The Granite crew constructs a cast-in-place junction structure on 4E North.
The Final Piece
Work on 4E North began in April. The approximately $114-million segment stretches between Hermosillo Road and Salinas Street, replacing existing lanes and adding a peak-period carpool lane in each direction. The Cabrillo Boulevard interchange will be reconstructed with two new bridges and right-hand freeway ramps replacing the existing left-hand ramps. A teardrop roundabout will also be constructed on Cabrillo Boulevard.
The reconstructed Cabrillo Boulevard interchange will include a teardrop roundabout designed to improve traffic flow at the Highway 101 northbound ramps.
The photograph, above, from Granite, shows just how much work has to happen before paving begins. Project Manager Colton Thomas reports that Retaining Wall 117, now under construction, reaches 24 feet in height and incorporates several steps in its footing. Bridge column foundations require five-foot-diameter cast-in-drilled-hole piles extending approximately 100 feet below grade, work that Thomas said could encounter challenging ground and groundwater conditions.
The drilling subcontractor pulls a drilling bucket from a cast-in-drilled-hole foundation excavation on Segment 4E North. Bridge column foundations extend approximately 100 feet below grade. Photo: Granite Construction.
Granite constructed a 9,000-cubic-yard abutment embankment surcharge to preload the native soil beneath a future bridge abutment. The surcharge must remain in place for 30 days to allow settlement to occur before the abutment is constructed. A corresponding surcharge is being constructed on the opposite side of the freeway.
Embankment work continues above the drilling operations. Photo: Granite Construction.
It is a revealing look beneath the pavement. Before motorists ever encounter the finished CRCP surface, an extraordinary amount of engineering has already disappeared underground.
A Contractor at the Design Table
But the larger Highway 101 story is not simply what Granite is building. It is when Granite became involved in deciding how to build it.
Under CM/GC, the contractor participates during design rather than entering the project after the plans are substantially complete.
Granite Senior Project Manager John Van Lenten says that collaboration directly influenced concrete pavement decisions. Granite participated in evaluating whether ramps should receive JPCP or CRCP based on factors including cost and placement access. The team developed concrete mixes with different opening ages according to schedule demands and worked through staging plans intended to preserve full lane widths wherever possible.
Foundation work proceeds beside live traffic at Cabrillo Boulevard, illustrating the staging and access constraints that shape construction on Segment 4E North. Photo: Granite Construction.
Perhaps the clearest physical expression of that corridor-wide approach is Granite’s onsite concrete batch plant.
CM/GC allowed the plant to be located in one construction segment while continuing to supply concrete to other segments even after construction in its original host segment had been completed. Van Lenten says that arrangement would not have been possible without the CM/GC process. Granite even bored a temporary electrical line beneath U.S. 101 and the frontage road to provide line power to the plant, eliminating the need for portable generators.
That same collaborative philosophy appears throughout the corridor.
Granite estimator Jesse Bishop describes it with two words: “Yes, if.” Rather than owner, designer, and contractor confronting problems from opposite sides of a completed set of plans, CM/GC puts the contractor, owner, designer and other specialists together early enough to identify constraints and evaluate alternatives. During preconstruction, the team collaborates on permitting, utility relocations, and right-of-way issues. Granite also works with Caltrans and independent estimators through an open-book estimating process intended to establish transparency and trust.
Drilling subcontractor crews work around a deep foundation drilling operation on Segment 4E North, one of the many activities taking place before concrete pavement construction reaches this portion of the corridor. Photo: Granite Construction.
Now that philosophy has reached its final mainline test.
On 4E North, the spectacular machinery in Granite’s photographs tells only part of the story. The drilling rigs, excavators, cranes and retaining structures show what is being built. CM/GC helps explain how the project got there.
And when the last stretch of CRCP is finally placed and U.S. 101 carries traffic across a completed six-lane corridor, much of the collaboration that shaped it will be invisible. Which, for infrastructure, may be the surest sign that it worked.