The recent Joo Koon crash would not have happened if the train was manually driven, or if the station master was there to guide it.
I lived in Japan for many years and often, there were train disruptions as people jumped into the path of oncoming trains.
The entire line would usually be down for about 25 minutes as staff worked to resume service.
For minor breakdowns, such as a railroad crossing that had malfunctioned, there were staff with whistles and flags at stations. The manual signalling system worked to ensure trains slowed down for that section.
SMRT should have emergency operation squads that are allowed to move quickly with sirens and flags to affected stations. Normally, only a short section is affected during a disruption, but an entire line may be halted for hours.
I come from the oil industry, where there are instrumentation malfunctions. The industry has built in a system of redundancy in sensors and safety procedures.
It takes severe disruptions to trigger a complete shutdown, as this is not only costly but will also immediately lead to massive flaring, and it takes a long time to safely restart systems.
Hence, the oil industry has built in manual overrides.
SMRT should also have standby semi-manual operations that can be activated during breakdowns.
Overall, Singapore has an excellent train infrastructure. The problems are those at the rail level.
Eddie Leong Yeow Fook