Replacement bus route

[elucidate]

Hi all,

Please have a look at the following itinerary:

I have a ticket for the above. It was issued in two parts:
First part: From LONDON TERMINALS to CAMBRIDGE | Route: AP GRT ANG ONLY | Validity: BOOKDTRAINONLY
Second part: From BROXBOURNE to CAMBRIDGE | Valid at 20:53 on 17 NOV 13

My question is this:
Instead of using my ticket to board the 20:10 bus from Chingford, would I be allowed to board the 19:58 rail replacement bus from Southbury (which is closer to where I live) to Broxbourne?

Essentially, what I'm asking is: does the driver look at where you're coming FROM or where you're headed TO?

Thanks in advance.

 

[30907]

Having checked the NR journey planner, you could perfectly well use an Advance ticket to travel via Enfield Town (as an alternative to Chingford) and the bus thence to Broxbourne.

However, the terms of an Advance ticket forbid starting short. It would be very obvious to anyone checking tickets that you were starting short at Southbury, as that bus (1) will have come from Enfield Town which is the train-bus interchange point (2) will not be the bus used by London-Cambridge passengers (who will have a non-stop as far as I can judge).

I would therefore strongly advise against trying to start short at Southbury.

 

[elucidate]

Having checked the NR journey planner, you could perfectly well use an Advance ticket to travel via Enfield Town (as an alternative to Chingford) and the bus thence to Broxbourne.

However, the terms of an Advance ticket forbid starting short. It would be very obvious to anyone checking tickets that you were starting short at Southbury, as that bus (1) will have come from Enfield Town which is the train-bus interchange point (2) will not be the bus used by London-Cambridge passengers (who will have a non-stop as far as I can judge).

I would therefore strongly advise against trying to start short at Southbury.

Thank you!