At the 2014 Alternative Clean Transportation Expo, Fool contributor Jason Hall sat down with Mark Aubry, Westport Innovations' (WPRT 0.53%)vice president of sales and marketing, to talk about how adoption of natural-gas vehicles is ramping up in the heavy trucking sector. 

Aubry talks about how the dynamic has changed, and how truckers, shippers, truck suppliers, and fuel providers are working to establish a complete solution to infrastructure, equipment, and support. Kroger (KR -0.78%) recently announced that it will introduce 40 liquefied natural gas trucks in Oregon and Washington, part of its first steps toward lowering the supermarket chain's fuel costs, while also reducing its environmental footprint.

Clean Energy Fuels (CLNE -2.30%) will provide fuel to Kroger, update Kroger's service facilities, and maintain the new fleet of natural-gas trucks. As Aubry says:

We've had [Clean Energy Fuels] come to the table and meet with us and with Kroger. We've had the OEM and the dealer come to the same table with the fuel partners. ... All of these pieces [are] coming to the table, saying collectively, "How can we make this happen for you?"

It looks as if now is a great time to invest in these natural-gas vehicle players. See more in the following video.