Speedway tie's oddly unexciting (6)
I believe the answer is:
sedate
'unexciting' is the definition.
(I've seen this before)
'speedway tie's oddly' is the wordplay.
'oddly' indicates alternate letters (letters in the odd-numbered positions are used).
'speedway'+'ties'='speedwayties'
The alternating letters of 'speedwayties' are 'SEDATE'.
(Other definitions for sedate that I've seen before include "Staid - tranquillise" , "Staid; put to sleep" , "Leisurely" , "Staid and sober" , "grave" .)