I was with the Federal Highway Administration (FHWA), which is one of many operating agencies of the USDOT. I was at the McLean, VA location in R&D. The environment is very pleasant there with free parking, though there's no Metro access.
The workplace environment was relaxed and business casual attire primarily with primarily cubicle type office style. There is a gym and plenty of outside space for walking with little traffic and noise.
There was a rapid change in the management over the last several years as people retired or moved on.
The hardest part of the job was keeping up with changing requirements in the acquisitions and publications departments.
The most enjoyable part of the job was the ability to influence direction of future highway technology.
Free parking, beautiful campus
No food within walking distance. No Metro access. Distance from USDOT HQ.