From the National Corridors Initiative website:

Transit managers lost a legendary colleague and transit riders lost a good friend last week. Edson L. Tennyson died last Tuesday after a long illness. He was 92, and his transportation career lasted for more than 70 years. At the time of his death, he was still planning further improvements for Washington, D.C.’s Metro Rail, which he had helped design fifty years ago.

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http://www.nationalcorridors.org/df3/df07212014.shtml#Tennyson