Photo: San Francisco County Transportation Authority Photo: CalMod.org Photo: Marcel Marchon Photo: Marcel Marchon Photo: CalMod.org Photo: CalMod.org Photo: CalMod.org Photo: CalMod.org

Have you seen the designs for the new Caltrain cars of the future? The proposed electrified commuter train features a sleek and shiny exterior, glassy windows, and ... doors four feet off the ground?

If you were wondering what these floating doors were for, you are not alone. When the rail line released the new train designs, many were scratching their heads about the double set of doors at different heights.

READ MORE: Here's what your commute will look like in the new electrified Caltrain cars

In an email statement, Caltrain representative Alex Eisenhart explained that the elevated doors are intentional.

"We've configured our new electric trains with multi-level boarding capability to accommodate future potential station platform needs of high speed rail," he wrote.

Multilevel boarding allows for faster boarding, which is of special interest to Caltrain since ridership has increased in the past years.

RELATED: How one Caltrain conductor is using humanity to improve your commute

The first electric train and their floating doors are anticipated to debut in 2021. The doors won't be used then, however, because multilevel boarding will not be available until a later date. In the meantime, only the lower-level doors will be used for boarding. The upper-level doors will remain closed.

Nikki Tran is an SFGATE intern. Email: nikki.tran@sfgate.com