Gary Zhou 
The San Bernardino County Transportation Authority (SBCTA) unanimously approved The Boring Company’s (TBC) Ontario Airport (ONT) Loop project to go from a single reversible tunnel into a bi-directional twin tunnel system.
Carrie Schindler, the Director of Transit and Rail Programs, presented the proposal to the SBCTA Board of Directors. She recommended modifying the Request for Proposals (ROP) for The Boring Company ONT Loop project to include building a bi-directional system instead of building a reversible single tunnel in the near term and expanding to a bi-directional system in the future.
The recommendation was made after ridership projections and analysis revealed that a bi-directional twin-tunnel system would ultimately benefit passengers in the long run. The Boring Company’s Ontario Loop was supposed to connect passengers with the Metrolink station. As such, the ONT Loop’s schedule would need to synchronize with the Metrolink’s arrival and departure times.
A study revealed that a single, reversible direction tunnel system would be effective and could accommodate the capacity of passengers passing through the transit system, provided that the vehicles used could hold a minimum of ten passengers. However, staff assigned to further study the proposal and ONT tunnel project also identified that a bi-directional system would provide “operationally superior, more efficient, and higher quality customer service” than a single-tunnel system.
They also discovered that a bi-directional system would synchronize better with Metrolink schedules. Passengers would be able to transfer from the ONT Loop to the Cucamonga Metrolink station much faster.
Switching to a bi-directional system would increase the capital cost of the proposed project. However, a Boring Company ONT Loop would still cost far less than an above-ground rail system. And Schindler pointed out that SBCTA recently received $26 million in funding from the American Rescue Plan (ARP) Act of 2021, which could offset the cost increase.
In February, the SBCTA authorized negotiations with TBC for a proposed Ontario Loop, a four-mile tunnel between Metrolink station and the ONT. The SBCTA estimated the tunneling project would cost $85 million, a fraction of an above-ground rail or light rail connection.
