just to second Christ, but also to add its a good idea to understand the plans of the bridge well too.
I assume you have a set of plans (paper or electronic) and if its anything like some bridges I've worked on plans can change 'midstream', and so its imperative you know what plans (version of) you have setout 'From' and if changes are made you need to be kept in the loop (obviously).
Bridges are 3 dimensional and so don't assume anything, check the plans and ensure you know what each component you are setting out does spacially.
Don't take the plans for granted. Egs, compare overall length with sum of what the parts add to. Do they agree?
Also check with the bridge builders/ supervisor so you both know what is being asked to be setout so you don't end up setting out something different.
Never 'assume' you understand, ask until you are absolutely without doubt.
Bridges start at the borrom and work up. A mistake at the bottom can be a disaster in a big time.
I have seen beams not fit piers. Thankfully not on my round.
Remember some of the above may seem excessive, but at the end of the day if something goes wrong, the first one to blame is the 'dope that set this thing out' . So keep good records, but don't be fearful, just careful.