Thank you for giving me the opportunity to assist you. I will give the best answer that I can with the information provided.
RRTA Tier 1 and social security withheld should not be greater than $6621.60 for the year, and Tier II benefits should not be greater than $3088.80.
From your description of box 14, it appears that this employee hit the max for Tier II (3088.80) and that the 5853.83 dollars corresponds to the RRTA tier 1 equivalent SS benefits (6.2% of taxable income) and teh $1369.05 corresponds to the Medicare equivalent (1.45% of taxable income). Wages subject to these taxes should have been approximately $94416.94.
If this is the only withholding for the year, the employer did not overwithhold.
Please see page 4 of the W2 instructions, and see Tip at the bottom. This will explain the max amounts. The $1369.05 is not combined with the 5853.83 because it represents the Medicare portion, and there is no yearly limit on medicare tax.