In the National Rail system, there may be different reasonable routes between two stations to make a journey. For example, to travel from Bournemouth from Horley (one stop north of Gatwick Airport), I can either first take a South Western Railway service to Southampton Central and change to a Southern service to London Victoria alighting, or take the South Western Railway service all the way to Clapham Junction and change to a Southern service back to Brighton there. Now these routes are codified into a manual called Routeing Guide and called Permitted Routes, which can be used on a ticket if not specified otherwise, and in fact, I am even permitted to travel via Basingstoke to Reading, then to London Paddington, take the tube to St Pancras, and get the Thameslink to Horley.

When a journey can be made with different routes, train companies can set different fares which are route-restricted, which serve as a form of competition between different train companies. For example, if I change at Southampton Central, the majority of the trip will be on Southern; if I change at Clapham Junction or at London instead, the majority of the trip will be on South Western Railway. And in the fares database, there are 3 different routes for a Bournemouth – Horley off-peak return ticket, from the most expensive to the least expensive (prices quoted with my 26-30 railcard):

• ✠ Any Permitted: £55.35 (set by South Western Railway)
• Not via London: £42.75 (set by South Western Railway)
• via Barnham: £20.95 (set by Southern)

As you can see, the via Barnham fare is much cheaper than the other two routes. In fact, via Barnham fares are known as one of the best-valued fares in the whole country that an off-peak return from Weymouth to Margate can be bought with just £22.75 with a railcard, which gives me one month of validity on the return journey along the southern coast with unlimited stops (including overnight) along the route!

In contrast, a Not via London ticket allows me to change at Clapham Junction or Southampton Central but not London, while an Any Permitted allows me to change at all three places. As there is a cheaper fare valid for changing at Southampton Central, the intended use of a Not via London ticket is to change at Clapham Junction; similarly, the intended use of an Any Permitted ticket is to travel via London.

Now, let me tell you a lesser-known quirk in the ticketing system.

If you want to travel on a more expensive route in one direction only, and a cheaper route in the other direction, you don’t need to buy the more expensive ticket!!!!!

In my case, I am planning a trip to Edinburgh on January 22-23. My original intention was to travel after work on January 21, and the only possibility I can arrive Edinburgh morning January 22 for a race is to either take the first easyJet flight from Gatwick on Saturday morning, or take a sleeper train from London to Edinburgh. However, as the price of the Caledonian Sleeper is so ridiculously expensive and can’t be discounted with a 26-30 railcard, that staying in a hotel near the airport and take the morning flight cost less than half of sleeping on a train, I took the option of releasing more CO₂ instead (well done HM Government in making train travel unaffordable), and travel to the airport using a cheap via Barnham ticket.

However, I really want to visit London to complete the missing bits last year, including visiting London Transport Museum and doing a bit of train bashing on the National Rail / Underground shared lines (including fast trains on the Metropolitan Line), and having a swim in the other unheated lidos (e.g. Brockwell Lido, while Tooting Bec Lido is closed to the public in winter season) there. Looking at my calendar, all weekends in January are already full and my first availability in February unfortunately falls on a date when engineering work takes place on South West Main Line where all trains with cheap advance tickets have to be diverted, leaving Paddington as the fastest option where cheap advance tickets are not available. Therefore, I finally decided to take a leave on January 21 immediately before my trip to Edinburgh, visit London, and do my weekly outdoor pool swim on that day.

My outdoor swims

Starting from the beginning of this year, I aim to do one high-intensity interval training session in a pool every week. As the pools near my home are all short course indoor pools which are too hot for me to sustain any high-intensity training, I have to find outdoor pools (lidos), preferably 50 m long, to do such training. The nearest one known to me is Guildford Lido which is only lightly heated to approximately 10-12°C on weekends during the winter season, however it is still too far away for commuting purpose at 2 hours minimum travel each way, so I can only visit there when I am not working.

Well-known lidos in London include:

• Tooting Bec Lido (unheated, 91 m long, closed to public (member only) in winter)
• Parliament Hill Lido (unheated, 61 m long, open year round)
• Brockwell Lido (unheated, 50 m long, open year round)
• Charlton Lido (heated to 25°C, 50 m long, open year round)

That means instead of going direct from my home to the hotel at Horley, I will instead go to London first, visit the city, and go to Horley after that. A via Barnham ticket from Bournemouth to Horley cannot be used for such journey, but a Not via London ticket can be used until Clapham Junction, where I can switch to a London Travelcard for the day in London, and switch back at East Croydon to resume the journey in the evening. Alternatively, if a cheap advance fare is available from Southampton Central to Clapham Junction, I can buy it and use it in combination with my original ticket. So, I have two choices in addition to a London Zones 1-9 Travelcard (I don’t want to use Oyster PAYG here as it will require me to get off the train at East Croydon and touch out there, either to switch back to a paper ticket or to start a new Oyster journey as the Horley Oyster cap is more than the Zones 1-9 Oyster cap + a off-peak single fare from East Croydon to Horley)

• Change the route on my existing ticket from “via Barnham” to “Not via London”, allowing me to travel from Bournemouth to Clapham Junction, then from East Croydon to Horley.
• Buy a new ticket from Southampton Central to Clapham Junction, and another ticket from Boundary Zone 6 to Horley.

Now the culprit comes. The change mentioned above is called a “change of route excess”, which can be done on either one direction of a return ticket or both directions. Note that only geographical routes can be excessed, a train company limitation (such as Southern only) cannot be excessed. In this case, I only want to travel via Clapham Junction in the outward direction, so I only need to change the outward direction. And the difference payable is half the price difference if I only change one direction, which in this case, is (£42.75 − £20.95) ÷ 2 = £10.90. In order to do that, I need to bring my ticket to a ticket office at a train station, as excessing tickets cannot be done online.

As this is a little-known quirk in the ticketing system, some staff may not realise it’s possible to do that. In such case, politely ask the staff to read the manual. After reading the manual, the staff accepted my payment and issued the excess for me, where a separate coupon is issued, the original one marked as excessed, and stamped together.

Furthermore, this procedure can be done to create loophole tickets as well if you are travelling only in one direction, where the return portion is discarded, demonstrating how ridiculous the price of a single ticket can be. In the above example, the total price paid is £31.85, which is not only cheaper than an anytime day single (there is no off-peak single) at £36.30, but also even cheaper than a single to Clapham Junction only which is priced the same! More ridiculously, a Bournemouth – Brighton not via London anytime day single is £30.60 which can perfectly be used to exit at Clapham Junction and cheaper than the one to Clapham Junction only. And by using the above procedure, using a Bournemouth – Brighton via Barnham off-peak day return (£15.50) as the base and excessing the outward portion to not via London, paying half the difference of £32.50 and £15.50, the total fare paid is just £24.00 for a triangular journey Bournemouth – Clapham Junction – Brighton – Bournemouth, and you are perfectly entitled to just exit at Clapham Junction and walk away without using the remainder of the outward portion to Brighton and the return portion at all, saving you £12.30 compared to buying a single for the exact journey, and as long as you depart after 09:00 it is as good as the “normal” ticket along the South West Main Line without the requirement of calling anywhere, unlike split ticketing which forces you to stop at a certain station. In short, for an off-peak journey from Bournemouth to Clapham Junction, the “normal” single price (railcard discounted) is £36.30, but by buying long to Brighton, the price is reduced to £30.60, and by buying a day return on a cheap route and excessing one portion of it, the price is further reduced to £24.00. This shows how ridiculous single pricing in this country is. This loophole can be used whenever a single is priced more than the average of the corresponding return and the return on the cheapest geographical route, and as “via Barnham” fares are commonly only less than half, or in longer journeys such as Weymouth – Dover, less than one-third of the fare on the London or Clapham Junction route, these return fares can be used to undercut ridiculous single fares in Southern England.