There are two railway lines running through Lower Edmonton, though only one has a station.
The line perhaps most of interest is the one through Edmonton Green which runs parallel to the A1010 high road. It runs from east from Liverpool Street to Bethnal Green where it branches north to Cambridge Heath, London Fields and Hackney Downs and branches again. One branch continues north to Rectory Road, Stoke Newington, Stamford Hill, Seven Sisters (Victoria Line interchange), Bruce Grove, White Hart Lane (handy for Tottenham Hotspur FC), Silver Street (on the A406 in Upper Edmonton) and Edmonton Green. Beyond Edmonton Green the line splits at Bury Street Junction with one branch serving Bush Hill Park and Enfield Town and the 'Southbury Loop' serving Southbury, Turkey Street, Theobalds Grove and then merging with the Lee Valley Line before Cheshunt.
The second branch at Hackney Downs goes via Clapton (after which there is a branch to Walthamstow Central and Chingford) and then runs north via Tottenham Hale (Victoria Line interchange), Northumberland Park (also good for Spurs), Angel Road (again the A406), Ponders End (the end of South Street), Brimsdown, Enfield Lock and Waltham Cross to Cheshunt and points north. This is the so called Lee Valley line which runs by the A1055 road in the east of Lower Edmonton. It is also used for the Stansted Express and longer distance services as far as Cambridge. When the stadium at Pickett's Lock seemed a possibility there was talk of a station being added but as it is the two nearest stations are Ponders End and Angel Road. Angel Road is particularly awkward to get to these days and has a very limited service anyway.
Today the lines are operated by 'one' who took over from WAGN (West Anglia Great Northern) on 1st April 2004 (an apt day for such a stupid name — the company name really is all in lower case which makes it awkward to write sensibly, as well as causing confusing in announcements like the '9:20 one service'). For a number of years the services through Edmonton Green have mostly been stopping services from Liverpool Street to Enfield Town or Hertford East (the off-peak service being two trains an hour to and from each). As of 2005, in the morning and evening peaks most services run to and from Cheshunt instead of Hertford East and some run non-stop to and from Seven Sisters. There is also one evening peak service that starts at Seven Sisters which seems a good idea.
A quirk in the timetable is a morning peak service from Cheshunt to Stratford and a return journey in the evening. This provides a welcome extra service to and from Seven Sisters even if it has few passengers after that. A few years back there was a late morning Enfield Town to Stratford service too. A journey like this is known as a 'parly', which is short for 'parliamentary service'. Back in the early days of railways companies were obliged by Act Of Parliament to run one train a day all stops with certain standards of accommodation and speed. The companies typically ran these services with their worst stock and often in the middle of the night. The term has been adopted for services that are only run because there is a lot of jumping through hoops required to completely withdraw a route and it is actually more practical to run one train a day to avoid this.
The December 2005 timetable has been published and this shows some changes to the local services. The off-peak service will now be to Cheshunt and not Hertford East, with the latter's two trains an hour now going via the Lee Valley line through Tottenham Hale. The slow services to Bishops Stortford and Stansted Airport from Liverpool Street have been dropped but the Stansted Express service will be every fifteen minutes during the day and will also provide half-hourly services to Bishops Stortford and Harlow Town. There will also be an hourly service from Stratford to Stansted Airport.
I haven't read the weekend timetables but apparently the Sunday service through Edmonton Green will be doubled to every fifteen minutes as it is during the week, with Hertford East the terminating point on the Southbury Loop services.
The diversion of the Hertford East services seems to be good news for Ponders End which will now have two trains per hour. Angel Road is losing its off-peak service totally though (not a surprise since it is so awkward to get to now) and only seems to be served by the peak hour Stratford services.
These changes are somewhat different to those that have been talked about for several months. The plans previously mentioned included services from Stratford to Hertford East and Stansted Airport. It was said that off-peak this would amount to one train an hour each way which would split/join at Broxbourne and run via Tottenham Hale. The Hertford East branch has limited capacity (apparently because of a single track section) which means the introduction of this service would require the withdrawal of one of the two services an hour to Liverpool Street via Edmonton Green. Presumably Edmonton Green would not have lost 25% of its off-peak services so this might have meant an increased service to Enfield Town. However it does rather seem that the Southbury Loop was going to be reduced to a one train an hour service. Well none of that made it to the timetable put on the 'one' website in September.
Edmonton Green is on the outer edge of zone 4 for ticketing. Travel times are about 8 minutes to Seven Sisters and around 25 minutes or so to Liverpool Street with the weekday off-peak service being 15 minutes to London and 30 minutes to Enfield and Hertford. The 'one West Anglia' website includes live departure information for the local stations as well as news of any service alterations and engineering works. There is also an alternative website with live departures information for Edmonton Green (and other stations).
The terminating station for the services via the Southbury Loop has varied a bit over the years. It has been pretty settled as Hertford East for a few years with Cheshunt, Broxbourne and Bishops Stortford also having been common. The December 2005 timetable suggests that it is back to Cheshunt again. The line picks up the Victoria Line tube at Seven Sisters. As far as I am aware all services are now timetabled to stop at Edmonton Green except for any that have been diverted from the Lee Valley line by long term engineering works.
There was a nice one page history of the train services with a simple but highly effective animated GIF on the "Lee Valley Online" site but when I followed the link in March 2007 the site had gone. However you can still see it via the Wayback machine.
As has been mentioned above, on April 2004 the West Anglia and Great Northern franchises run by WAGN were separated. The West Anglia one (the local suburban services and the Cambridge mainline) was combined with those of the Anglia Railways (mainline services and some local services more out Norfolk way) and First Great Eastern (other local and suburban services) to form a 'Greater Anglia' franchise. This means just one operator at Liverpool Street which seems sensible. The operator is National Express (parent of WAGN and others) under the name London Eastern Railway Ltd and the quite cretinous branding of 'one'.