Are travle reimbursments made to board of directors taxable income?

If the reimbursement are in fact reimbursements for travel costs incurred by the board of directors, then they are NOT taxable.

However, some companies try to get around the taxation of fees paid to directors by paying extravagant travel cost reimbursements. IRS Pub 1542 publishes acceptable per diem and lodging costs for everywhere in the United States. If the reimbursements gross exceed those rates, the IRS becomes suspicious and will audit the directors' tax returns.