Question:
I know that Portugal shifted from driving left to right in 1928. I could imagine, that the trams had only left doors when shifting. How did Portugal cope with this? Did the trams continue in the left side for some time, or was it properly planned as in Sweden, where public transportation introduced double sided door vehicles starting 10 years before cut over i 1967.

Answer:
In 1928 all trams in Portugal were fully symmetrical: double-end with entrances / exits at both sides. So for the trams there wasn’t anything to change. The first unidirectional trams in Porto were put in service in 1946, the first in Lisboa in 1951. Sintra, Coimbra and Braga never had single-end trams with entrances at one side only.
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