buses

Usage notes
Buses is the usual plural of in both British and American English, ignoring the typical doubling of consonants after a short vowel. The form is less common. This may be because it was once understood as a shortening of omnibuses, which would be the regular plural of in both British and American English, if the word is understood to be accented on the first syllable. Doubling is seen more frequently when bus is used as a verb.