The Caltrain Electrification Project is a significant infrastructure initiative in California to convert the existing Caltrain commuter rail system from diesel power to electric power. Led by the Peninsula Corridor Joint Powers Board in collaboration with Caltrans and the Federal Transit Administration (FTA), the project seeks to enhance performance, efficiency, and sustainability.

The project involves installing overhead catenary wires, supporting structures, and traction power substations along the Caltrain corridor. Additionally, Caltrain stations and platforms will be upgraded to accommodate the new electric trains. Construction began in 2017 and is expected to be completed by 2024, resulting in faster and more reliable train service, improved air quality, and reduced noise pollution.

The estimated budget for the Caltrain Electrification Project is approximately $2.5 billion. Funding comes from federal, state, and local sources, with a significant grant of $647 million provided by the FTA. The project's budget has undergone revisions due to challenges and delays — its original budget was just $1.5 billion — but the current estimate reflects the costs associated with electrification infrastructure, new electric trains, station upgrades, and related expenses.

Once completed, the project will offer substantial benefits to Caltrain riders and the broader community. These include enhanced speed and reliability, reduced emissions, and improved integration with regional transit systems such as the future California High-Speed Rail, and local leaders hail the Caltrain Electrification Project as a crucial step towards a more efficient and sustainable transportation system in California.