Originally Posted by
InvisibleBison
I'd say that base land speed includes the bonus from haste. The glossary entry for base land speed, on page 305 of the PHB, defines the term as "The speed a character can move while unar-
mored", and both expeditious retreat and longstrider say that they increase your base land speed, which shows that it's not a constant. Even though haste doesn't have similarly explicit language, I think it's reasonable to say that all increases to speed are considered part of your base land speed while they are in effect.