According to the Congressional Handbook, the bible of dos and don'ts for House offices, "commuting expenses are not reimbursable." These costs are defined as "transportation expenses incurred by the Member or employees between their residence and duty station." A spokesman for the Committee on House Administration confirms that the use of a government-leased vehicle for commuting purposes and the use of a public employee as a driver are both violations of House rules. Of course, every lawmaker is expected to know the Congressional Handbook. But Jackson Lee was also provided a copy of these guidelines when her office leased the car that she rides in to work.
Found here:
http://www.weeklystandard.com/content/public/articles/000/000/000/867aejst.asp