After start, car close to office attempts to bypass key roads (8)

'key roads' is the definition.
'arteries' can be an answer for 'roads' (artery is a kind of road). I'm not certain of the 'key' bit.

'after start car close to office attempts to bypass' is the wordplay.
'after start' means to remove the first letter (I've seen 'after starting' mean this (only the letters found after the first are used)).
'close to' indicates one should take the final letters (the 'close' to the word).
'attempts' becomes 'tries' ('try' can be a synonym of 'attempt').
'to bypass' means one lot of letters goes inside another (some letters go round or bypass others).
The final letter of 'office' is 'e'.
'car' with its first letter removed is 'ar'.
'e' inserted within 'tries' is 'teries'.
'ar'+'teries'='ARTERIES'

Can you help me to learn more?