Definition of "sighting"

However, many people—including railwaymen—are only beginning to realise how great is the amount of civil engineering work necessary to achieve adequate clearances for high-voltage overhead equipment under bridges and tunnels; what is involved in the re-signalling needed to permit the increased throughput of traffic (in some places it is unavoidable, to afford better sighting of signals obscured by overhead electrical gear); [...].

1961 December, “Planning the London Midland main-line electrification”, in Trains Illustrated, page 719