Motorway for UK, Ireland, New Zealand and parts of Australia; freeway (I think) for most of North America and Australia.

Although I can't find an instance of this precise combination of words, I can't see what else it could be.

Here's a very similar example from Australia:

"Two economic entities were established for the development of [the] project: Hills Motorway Limited (HML) and Hills Motorway Trust (HMT). HML is a limited company, which was granted a concession [...]."
https://books.google.es/books?id=sCTmc6GEbNsC&pg=PA190

Here's a relevant US reference on a public-private partnership in Texas, though no reference here to a trust:

"I - 635/LBJ Freeway (Concession)"
http://itstexas.org/sites/itstexas.org/files/presentations/I...

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Note added at 1 hr (2018-08-19 01:09:41 GMT)
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They evidently established a trust to administer the concession, and this is a meeting of the trustees' committee.