There is indeed. There will be a longitudinal wind load on the substructure (piers) and is covered in 3.8.1.2.3. There is wind on Live Load both longitudinally and transverse at a distance 6' above the top of deck. Section 3.8.1.3 covers wind in the transverse direction in the first few paragraphs. I'm not sure what version of AASHTO is required on the exam, but the latest 4th Edition with 2008 Interims has the loading for transverse and longitiudinally on live load in Table 3.8.1.3-1. It maxes out at 0.038klf at a 60° angle. The "normal component" is the transverse wind and the "parallel component" is the longitudinal wind on live load.
You can have wind on the super and substructure both longitudinal and transverse (substructure only if piers are involved). The transfer of loads (moment arms) vary depend on which one you are analyzing. Some loads are transferred at the bearing to the substructure (longitudinal winds), and some are transferred at the point of loading. As with building design, wind loads on bridges can get complex as well. Throw in wind at different angles and you have a perfect case for a wind analysis Excel spreadsheet
In regards to the SE exams, I highly doubt you'll have to worry about wind load moment arms. Typically wind is only a concern when you have deep plate girders and/or tall piers.
As far as the wind pressure on exposed area, you are basically taking the exposed area that wind will be applying pressure to....similar to buildings. Transverse wind loadings are applied the entire span length times the height of the superstructure. The end area of the pier is also calculated. Longitudinal direction, it should only be the width x height of the pier. There is another case, which is uplift due to wind. See 3.8.2