n. — Food & Drink, Central and Eastern Canada
a food cart selling French fries and other fast foods.
Type: 1. Origin — The term is used almost exclusively in Canada (see Chart 1). The expression is likely inspired by the French name of its Quebec predecessor (see the 1948 quotation), as chip wagons were spreading from Quebec into Ontario and the Maritimes (as evidenced in Chart 2), with some use in Manitoba. Today, the term is more a marker of Ontario English and Maritimes English than Quebec English.
See also ITP Nelson, s.v. "chip wagon", marked as "Chiefly Ontario", COD-2, which labels it "Cdn".
See also: poutine (meaning 1)
- 1944  Roland Guindon, seven-year-old son of Mr. and Mrs. L. Guindon of 23 Brebeuf street, Hull, was seriously injured last evening when he fell under a potato chip wagon near his home. 
- 1948  The white "patate frite" wagon which (motor driven or horse drawn) is such a familiar sight all through Quebec - and not unknown in Eastern Ontario - was patronized by young and old and still doing a brisk business when the show - an excellent movie, all in French - was over. The potatoes were sold in little paper cups and each customer reached for a bottle of clear liquid on the counter of the wagon. The bottle had a sprinkler top such as we use in dampening clothes on ironing day, and it contained, we learned, white vinegar. 
- 1958  City council is studying a proposal that potato chip wagons and other vehicles in which food is cooked be banned from Hull streets. 
- 1970  [...] in our day, which, if you're interested, was during the Second World War [sic] I remember the horse-drawn chip wagons used to line up one behind the other at lunch and recess until the Principal put a stop to it. 
- 1980  Then take the first turn east, which will put you on Durham County Road 4 and take you back to Toronto by way of Pickering, where if you're not too late you can still catch the fish and chip wagons before they close. 
- 1986  And without a map, how will they be able to get to Loretta and Maurice's Chip Wagon for that $4.65 plate of french fries, cole slaw and perch fillets? 
- 1992  Outdoor steam-powered espresso carts are to Seattle what chip wagons are to Ottawa. 
- 1999  Last night, aldermen approved amended legislation that prohibits retail sales on vacant city lots but excludes the market square, chip wagons and the sale of food, farm produce and motor vehicles. 
- 2007  It wasn't that long ago when 'eating local' meant stuffing your face at a chip wagon down the street. 
- 2010  "There is one single, unifying element that defines our Canadian culture in absolute terms," writes Chadwick, "a skein that runs through the warp and weft of the Canadian psyche. It's not our language, not our universal social programs. . . It's not even the animosity we hold each other in -- the bipolarization of English versus French, east versus west, everyone versus Ontario. No, -- it's the chip wagon." 
- 2015  An on-site chip wagon offers poutine, burgers and fries, while cotton candy and drinks are available at the canteen. 
Images:
Chart 1: Internet Domain Search, 23 Aug. 2012
Chart 2: Regional Domain Search, 15 Nov. 2015