No - the Met line is significantly more complex than other lines and there are different rules depending on exactly where you are. It's worth noting that these rules are not specific to empty running - trains running 'fast via the local' or otherwise non-stopping a station in passenger service can also make use of these overlaps.
There are some additional anomalies (mainly due to things like tripcock testers), but broadly speaking speed limits are as follows:
- Moor Park to Amersham via Main Lines excl. Rickmansworth - 60mph
- Rickmansworth - 25mph (PSR)
- Harrow (excl.) to Moor Park (excl.) via Local Lines - 50mph (Moor Park/Harrow 15mph)
- West Harrow/Rayners Lane - 30/20mph
- Wembley Park (excl.) to Harrow via Local Lines - 25mph
- Wembley Park (incl.) to Harrow via Fast Lines - 50mph
Whilst I think the point has come across, some of the terminology and explanations given here are incorrect, although I appreciate that this seems to be coming from a T/Op perspective whereas my own view is from the (LUL) signalling side. I won't get into too much signalling detail and will focus primarily on the Met, but it shouldn't go uncorrected;
- As a general rule, all London Underground signals have 'full speed' overlaps. These aren't 'extended' (something entirely different) - it's the basic principle of London Underground signalling design. If a train has a SPAD on a signal at line speed, it will stop before it can conflict with a train standing at a signal ahead. This is possible largely due to having specific stock with similar characteristics on each line, all of similar lengths. A fair amount of the signalling work being carried out on the Piccadilly line is to ensure that these principles hold true for the new stock, for instance.
- There are always exceptions (like everything on the railway!) - a lot of the worst examples of 'compromised' overlaps have now been abolished, but where multi-home and/or draw-up signalling exists this principle doesn't always hold true. The biggest exception by far is for station starting signals, which - again, generally - do have reduced overlaps.
- Reduced signalling overlaps on station starters are standard practice on LUL and account for trains slowing, carrying out station duties and accelerating again. Enforcing a reduced speed when travelling non-stop protects the integrity of the signalling, and also proves useful for things like tripcock testers which have their own restrictions. If a train was to SPAD a station starter in a 'winding up' incident (starting away from the platform on a red), or to have a SPAD at the reduced speed, it would stop within the protected area and not come into contact with a train ahead. If a train was to go past one of these signals at line speed and have a SPAD then this may not entirely hold true.
- The Metropolitan line is special. Largely due to its legacy of being the Metropolitan and Great Central Joint Railway, but also due to the Fast, Semi-Fast and All Stations service patterns (and the many, many historical variations thereof) it was noted that requiring all trains to slow down for stations would significantly impede capacity and many of the benefits of the four-tracking project. As a result higher speed overlaps were provided as listed above (generally) meaning that all trains can dispense with the need to run through stations slowly and if they do have a SPAD they will come to a stand within the protected area. This is further enhanced on the Main Lines with the national rail-style multi-aspect (three/four) signalling, providing more notice of adverse aspects ahead. The key difference from NR is that full speed overlaps are still provided throughout on the majority of signals meaning that if your 60mph steam train has a SPAD it will almost certainly stop before conflicting with anything - yes, the signalling on the Main Lines is steam era and largely is unchanged since then.
- Extended overlaps are a separate concept entirely, but worth mentioning - with regards to the Metropolitan line, this is a specific set of circuitry that is operated during the autumn leaf fall period (it's due to be switched in this year imminently) and extends those signalling overlaps even further, as the name suggests. Coupled with a reduction in line speed on the southbound only from 60mph to 40mph, these overlaps (along with sequential signalling) mitigate against the effects of railhead contamination and hopefully prevent any serious incidents from occurring as a result of uncontrolled SPADs (sliding). Essentially these will hold signals at danger for longer, requiring greater separation between trains and that every track circuit drops and picks back up in the specified order.
Two words of caution: firstly, the signalling implementation on the Just Trains Metropolitan line route is, at best, an approximation. Particularly with some of the multi-home signalling things won't behave correctly, and it's very easy to collide trains when driving at line speed to the signalling seen without intending to - in reality there would be no collision risk. OTTOMH this won't impact anything at the top end, but is worth mentioning - I think it
may be an issue around Wembley - some of the legacy signalling around there was quite interesting. Secondly, whilst LUL is all one happy family with a share rule book, there are many differences between lines, even before things like ATO are considered. An understanding of the Piccadilly line will help with getting a grounding of stuff on the Met, but it won't cover a lot of the intricacies and exceptions, so is something to bear in mind depending on what level of realism you're looking for. Indeed, a re-working of the LUL Rule Books a few years ago placed a lot more emphasis on the relevant Line Supplements such is the breadth of scope nowadays, including moving many long standing procedures away from the pan-LU Rule Books and into the specific Line Supplements. We're not quite at a rule book per line, but it's definitely a useful way of thinking for a lay person.
HTH.