Hi there,
If you are going to KEGS than Gidea Park to Chelmsford by train is the way that the young people do it. I know a few that do the commute but the two I know well (one CCHS and one KEGS live within walking distance of Gidea Park station. It is decent commute but Crossrail has been causing more frequent disruptions lately. When on the train into London I see KEGS/CCHS uniforms travel all the way to Stratford so at least Hornchurch is Zone 6.
To go to Westcliff the people I know use
http://www.crestcoaches.com/transport-t ... r-schools/There are many people that travel from Hornchurch and if you are on the other side of Hornchurch near C2C in upminster then Chalkwell station is a bit of a walk, but again, lots of uniforms going to Central London from the schools.
We moved from Hornchurch to Westcliff so our children could walk to WHSG and WHSB. I still travel up the A127 to Gidea park when I am working off peak as you can't beat £3.10 to the Westend but if I work during the day I take C2C to avoid A127 carpark rush hour. The buses get there quickly as they are doing the reverse commute, If you are travelling into London on the A127 you see many different buses coming down off the A127 to the local roads to the schools around 8am.
I will check with my sons friend at the boys school to see if he takes a different bus than Crest when I get a chance.
* UPDATE Apparently Crest is full this year but Maymist also does a run.