A Great Western Railway service from London Paddington speeds past Westbury on the avoiding line. The tracks on the right lead up to the station for trains that need to call there. The bridge originally only had the arch on the left when all trains went to the station but the second arch was added in 1933 when the avoiding line was opened and the station line was moved to the new arch.
<a href="//commons.wikimedia.org/wiki/User:Geof_Sheppard" title="User:Geof Sheppard">Geof Sheppard</a>
CC BY-SA 4.0
<span class="int-own-work" lang="en">Own work</span>