"John Rowland" wrote in message
...
"Martin Underwood" wrote in message
s.com...
"John Rowland" wrote in message
...

If a brand new road is built these days, what are the
guidelines about level crossing versus bridge?

This is an issue in the plans for Watford Junction. Level crossings are
considered to be unsafe, and I don't think any more will be installed on
straight roads... but at Watford the planned road is (horizontally)
curved,
and a hump-back bridge on a curved road is considered to be even worse
than
a level crossing, so a level crossing might be installed there.

In that case, I'm surprised no-one's suggested a hump-back bridge to take
the railway over the road ;-)

I presume that if this is a brand new road (as your phrase "planned road"
implies) there must be other constraints such as existing buildings which
mean that there has to be a bend at all. Whereabouts is it?

If it's a level crossing and it's on the main line (as opposed to the branch
to St Albans) that the delays for road traffic will be horrendous given that
it would probably be a full-barrier crossing linked with the signals, rather
than an AHB activated by the trains which would require less lead time
between the barriers going down and the train arriving and would probably
allow the barriers to be lifted briefly between successive trains.

In article m, Martin
Underwood writes
This is an issue in the plans for Watford Junction.

If it's a level crossing and it's on the main line (as opposed to the branch
to St Albans)

or the Watford High Street branch (though very little of that is at
ground level).

that the delays for road traffic will be horrendous given that
it would probably be a full-barrier crossing linked with the signals, rather
than an AHB activated by the trains which would require less lead time
between the barriers going down and the train arriving and would probably
allow the barriers to be lifted briefly between successive trains.

An AHB is not permitted where there are more than two running lines, or
where speeds exceed 100mph. Furthermore, they are not permitted if
there's any practical risk of a traffic jam "blocking back" as far as
the crossing, or if for any other reason the road exit could easily
become obstructed.

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Clive D.W. Feather, writing for himself | Home:
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