Edit: 10/01: reuploaded the screenshoots of the bridges.
Following the guide below, you will get also this achievement if you choose truck for the bridge test:
You might also, want to work, one on one with the solution of the tank trucks, cause in these levels you unlock the extra budget right after the truck level cleared.
Level 1:Level 2:Level 3: Level 4: Level 5:Level 6:Level 7:More detailed view:
Level 8: