CNG and LNG is slowing down drastically now that the Government isn't giving tax credits, etc to the businesses any more. I drove a CNG 18 wheeler for 3 years and Hated that thing (you are sitting on top of a time bomb in case some in an accident hits your fuel tank). A good bit of fuel stops were 300 or more miles apart and only selected truck stop carry that fuel just to get there to find out their pumps were out or down. Then you have to get towed another few hundred mile to fill up. You can't just put that sough in a can and bring it out when you run out. Pilot and Flying J have stopped expanding on those fuel locations. The company I was with at that time got rid of every one of them after their 3 year deal ran out. I also use to drive a CNG Tanker with Raven Transport for 3 of my 18 years I was with them, they were under contract to Clean Energy. Raven eventually got out of the CNG and LNG delivery business.
Just about the only ones still using it has dedicated tanks on their yard and returns to their yards when fuel is needed. Even UPS keeps running out of the fuel quite often. I sometimes would get emergency call to refill some UPS trucks sometime with my tanker when they were on the side of the road if I happened to be near by. You are now talking about big Bucks $$$
Besides, not everyone is certified to work on a CNG vehicle and you can't repair or park them in a confined building unless it ventilated to certain specifications (with Fans and gas sniffers, warning and fire prevention systems).
Remember CNG and LNG are not interchangeable with each other.
Here is a link to the fuel locations we have and how far apart they are if you are traveling: avilable:
https://www.cnglngstations.com/