For this achievement you'll need to get 1000 exp by parking Heavy Cargo Pack DLC cargos.
The Heavy Cargo Pack cargos are the following:
- Asphalt Miller - Writigen 808
- Concrete Beams
- Dozer Crawl - Z35K
- Industrial Cable Reel
- Locomotive - Vossloh G6
- Metal Centering
- Mobile Crane - Rex-Tex 45
- Transformer - PK900
Go to the quick job listings and filter on length of the route, from lowest to highest. The shorter the whole route, the quicker you can park the truck, the quicker you get this done. Now at the top left, click open de drop down menu that shows the types of cargo and choose the bottom left option (Heavy). So now your job list is filtered on shortest routes first, and on only heavy jobs. Find the shortest route with any of the above cargos and complete it.
Don't forget to manually park the truck at the end, and to be as quick as possible, choose the highest difficulty parking option, which gives the most exp. Keep doing this until you're at 1k or above exp from parking any of the above 8 cargo types, and the achievement should unlock.
Other heavy cargo types don't count, they need to be part of the Heavy Cargo Pack dlc.