Sighting Distance

[Peter]

Dear Members,

For headway calculations we are taking sighting time 10sec as a assumption. For sighting distance calculation whether we have use maximum permissible speed or headway speed ?

Please clarify.

You would use maximum permissible speed since this is the speed at which a train could be approaching the signal. The headway speed is a theoretical speed that you use for design - ideally all of the trains will be running at linespeed!

If you are still unsure on this, please come back.

Peter