The Grindewald line is also available https://www.youtube.com/watch?v=Ubf23ZYkmGU

 
The park and ride site is very large. I saw it under construction when I stayed in Grindelwald last year. I have also travelled the line to Lauterbrunnen but it is fascinating to see it as a driver's eye view

 
Increasing motor congestion on the roads to Lauterbrunnen and Grindelwald from Interlaken has led the local and national Swiss Governments to propose, build and open a new Park and Ride site on the Berner Oberland Bahn (BOB) using land from the cold war Swiss Military airstrip to the south east of Interlaken at Matten. The scale of the site is enormous as can be seen in this video, of the now opened facility, recently published on YouTube by the prolific AKSense - Zurich transport channel.

https://youtu.be/zhet3eo3oQk?si=PsNiWjUdhFsvNwd3&t=141

This has not, like many such schemes, been done 'cheap'.

(The whole video shows the line from Interlaken Ost to Lauterbrunnen).

This project is the latest in a series of developments across the Bernese Oberland which has included extensive doubling between Wilderswil and Zweilutchinen, a new tunnel SE of Zweilutchinen on the Grindelwald line removing a notorious riverside kink in the infrastructure. Repair work across the network following intense storm damage in 2005. The major work however being the new Eiger Express Cableway to Eigergletcher from Grindelwald Terminal which has involved a new station between Grindelwald and Schwendi, Grindelwald Terminal and reworking of the Jungfraubahn immediately before the entrance/exit from the tunnel through the Eiger to Jungfraujoch.

These works are all visible in videos on the same and across other channels.