I-405 Sepulveda Pass Widening

The I-405 Sepulveda Pass Widening is a highway improvement project that will add a 10-mile HOV lane on the northbound I-405 freeway and improve supporting infrastructure such as ramps, bridges and sound walls. Additionally, the I-405 Widening Project will reduce existing and forecasted traffic congestion and enhance flow by adding freeway capacity in an area that has historically experienced heavy congestion.

BA Inc. serves as a sub-consultant to HNTB and performs Civil Design work. BA Inc. provides utility design and coordination services for all utilities including sewer, potable water, drainage, and horizontal and vertical design for dry utilities. Additionally, as a part of our drainage design, BA Inc. prepares hydrology maps and performs hydraulic calculations. Relocation design consists of profile preparation, cross-section creation, and development of construction details which are required due to the utility congestion, limited space, and complex construction within the project area. Respective tasks require extensive interaction with CALTRANS, LABOE, LACFCD, LADWPWS, LADWPPS, other agencies, and numerous utility companies throughout the design review process.

Several critical design features are included in the utility scope of services. A brief listing of key critical design features for which BA Inc. provides engineering design services include:
• Preparation of utility relocation plans for utilities impacted by several bridge widenings and wall construction activities.
• Design of wet and dry utilities within bridges which will be widened in order to accommodate potential seismic displacement.
• Design of utilities to avoid critical and/or immovable distribution lines.
• Horizontal and vertical layout of utilities in heavily congested utility corridors.
• Coordination of design elements with multiple agencies responsible for project approval.

Numerous challenges exist on a project of this magnitude. BA Inc. has been able to meet these challenges and deliver under an extremely accelerated design schedule, resolve design issues arising from the participation of several agencies with various design criteria, and design new utilities within a fixed and extremely limited public right-of-way.

Project Highlights
• 36” Trunk line water design through Sunset Bridge for LADWPWS with expansion joints to accommodate seismic activity
• Innovative sewer design prevented shutdown of prominent I-405 on-and-off ramps which reduced negative impact to the community
• BA Inc’s. extensive experience with the agencies associated with the project expedited design approvals.