NYC Transit To Provide Late Notes
You don't need to worry about getting in trouble from your boss if the subway makes you late in New York City anymore. The transit authority will give you a late note. Passengers can request delay verification letters over the phone. NYC Transit verifies the date and time of the delay and sends an official note in the mail in one or two weeks. It mails 34,000 notes a year. An online system is currently in development. It won't be long before someone makes a website that lists all the late trains for your verified excuse needs.
JR already does this...when there's a delay b/c of someone jumping in front of a train or whatever, there's stationmasters passing out little slips of paper with the date/time and their stamp on it.
However, this does not help much if there are a half a dozen consultants or an important customer waiting for you in the office. The transit companies seem to assume that everybody taking transit has a McJob, where this actually matters.