Caltrain is adding two new trains and restoring four others in response to an all-time high in ridership reached over the summer, the agency announced Tuesday.

In June, Caltrain averaged more than 50,000 riders each weekday -- a record high in ridership for the transit agency, according to spokeswoman Christine Dunn. Additionally, Caltrain has experienced 24 months of consecutive increases in ridership, prompting the agency to add and restore trains previously cut due to budget contraints, Dunn said.

The additional service will roll out Oct. 1. The new schedule includes "shoulder" trains, or trains on the edges of the regular morning and afternoon commutes, to increase travel options for commuters.

It also adds either a Palo Alto or Sunnyvale stop to 12 limited service trains. The additional stop should give customers more flexibility in planning their commute without a significant increase in the overall operating time, Dunn said. "These changes are a response to the high demand we're seeing for Caltrain services," Chuck Harvey, deputy chief executive officer for Caltrain, said in a statement.

"We're hoping to reduce some of the crowding on peak-hour trains by providing more options for our customers. We're hoping these changes will provide a short-term solution while we continue to plan for faster, more frequent service to more stations through corridor electrification," he said.

Electrification is part of Caltrain's modernization program, which will also fund the purchase of electric vehicles and install an advanced signal system, known as CBOSS positive train control.