One feature common to many major cities around the world is public transport. These services should be the lifeblood of cities, yet passengers know this isn’t always the case. Instead, there can often be scenarios that make people question the reliability of these systems that are designed to streamline daily commutes.
“Many of us have watched the ETA of a service countdown from 10 minutes, anticipating the arrival, only for it to jump unexpectedly to 20 minutes, then down to five and up again to 14,” NEC Head of Smart Transport ANZ/Global COE lead Mark Messenger told ABC.
“Such erratic behaviour isn’t just frustrating – it’s an indicator of a deeper systemic problem known as the ghost bus phenomenon.”
The ghost bus phenomenon refers to a bus that never arrives at the actual vehicle arrival time slated on timetables, or buses that appear to vanish from the ETA system, only to reappear sporadically. Another similar experience to waiting for a ghost bus is the ‘long minute’, where a bus that’s stuck in traffic doesn’t adjust its ETA and instead shows a historical average time that doesn’t take into account present congestion.
A ghost bus could also be involved in the case of a ‘deadheading’ vehicle, which is when a bus is en-route to its starting position for its next trip and running late, but the system fails to provide an accurate departure time from its first stop, meaning all arrival times are wrong from the start.
You may think you’re unique for experiencing these frustrating waits, but data from the first NSW Bus Industry Taskforce report released in August last year indicates that more than 10 per cent of buses in the state are impacted by the ghost bus phenomenon.
Closely relating to the ghost bus is the ‘zombie bus’, which is when it disappears for a while but reappearing when it re-joins the original route. Due to technical issues or other reasons, a bus might operate without being tracked before turning up unexpectedly, with some commuters referring to these services as ‘bonus buses’.
“Several operational and system-based reasons give rise to ghost buses,” Messenger says.
“From an operational perspective, discrepancies between actual operations and planned trips, unexpected diversions or incorrect route updates can cause such anomalies.
“Systematically, the rigidity of scheduling and arrival time prediction systems often take the blame. Some systems, once locked in for the week or month, resist modifications. In other instances, auto-assignment logic mistakenly allocates an out-of-service vehicle to a particular route.”
NEC Australia is one such company looking to combat the rise of ghost buses and identify the main problems causing these service disruptions. What it’s found is that ghost buses can be identified through prediction performance metrics.
When there’s no corresponding actual arrival for a predicted bus, the data gets excluded. By analysing this unmatched data, transport authorities can pinpoint the onset and duration of ghost bus incidents.
“Heatmaps showcasing ghost buses offer intriguing insights into driver patterns, which, when combined with automated assignments, can pave the way for systemic corrections,” Messenger says.
Fortunately, the advancement of technology is helping offer some solutions to tackling the ghost bus conundrum.
The NEC Mobility Operations Management System is one example that includes features allowing adjustments to operational duties in real-time, focusing solely on the current day. By integrating with dispatch systems and real-time updates, the system can support the management of planned diversions and forecast more accurate future trip ETAs through its NEC Mobility Inform system.
This system provides real-time updates on the arrival times for buses based on actual data from the buses or predicted arrival times generated by using AI-based prediction engines to determine arrival times based on historic and actual bus fleet performance and traffic conditions.
Features like ‘deadhead’ navigation use the recently released Bus Turn-by-Turn navigation system and one touch driver updates on the NEC Multi-Application Driver Tablet (MADT) to allow drivers to notify the system of route diversions or stop omissions.
Messenger says the use of technology and increased understanding should be combined to tackle the ghost bus phenomenon.
“To completely dispel the ghost bus phenomenon, a multifaceted approach is vital,” he says.
“Supporting drivers and operational staff with the right technology can prevent undue assignments leading to ghost buses. Introducing real-time dynamic run-cutting and implementing visualisations to discern driver patterns can be potential game-changers, while recognising ghost buses as a key performance indicator (KPI) will also push authorities to address and reduce these occurrences proactively.
“While the enigma of ghost and zombie buses can unsettle any regular commuter, the evolving tech landscape promises a future where public transport is more reliable, efficient and ghost-free.”