Scenarios Are King: Scheduling And Planning For The Social Distancing Era

Introduction

In the past several months, public transportation is facing a staggering amount of uncertainty. First, services were cut and ridership dropped. Then restrictions were eased and service changed some more. Funding, ridership and additional factors turned what was once a stable operation into a service that changes all the time. In this new world, agencies and operators must come to terms with a new reality: the reality of multiple scenarios.

In the world before Coronavirus, there were several constant truths: ridership was all-important, the metric that proved that the transportation service was worthy of the public’s trust. Funding was more or less constant. Another truth was that service and the resulting crew and vehicle schedules seldom changed. The absence of large changes is also due to the fact that planning and scheduling public transportation is notoriously difficult and requires a lot of work, expertise and technology as well as regulatory and/or public approval.

All this has changed. The sudden realization that service has to be reduced during the early lockdown phases has been replaced by the understanding that service is bound to change yet again, forcing the industry to come to terms with a new reality: there are going to be many service scenarios that need planning and scheduling, and this is going to impact how the industry uses technology and understands its operational results.

This blog will discuss several aspects of the need to change planning and scheduling often and the impact they have on current industry practices.

Making service reductions

What happened

When the Coronavirus hit, we heard a similar message from agencies all over the world. They needed to prepare for driver shortages. We were asked to help model service in case of two scenarios – 10% or 25% driver absenteeism, as a result of quarantines or infection. Early on, this was the initial concern in the industry – protecting bus drivers and dealing with the ramifications of crew shortages. Even before the virus, the issue of driver shortages was a core focus of many scheduling exercises, looking to reduce duties and roster rows. Yet, as lockdown approached and the need to reduce service became evident, the driver shortage concern became secondary.

Indeed, after the industry began disinfections, fare elimination and rear-door boarding, the main concern was how to cut service. Many agencies moved to some form of weekend service. Others cut service span, frequency and coverage, based on either ridership data or estimates as to the demand for their services when lockdown is in effect. At this point, making service changes solely based on driver shortages wasn’t the core need.

1. Scheduling implications: driver shortages

In general, driver shortages are best dealt with by applying a global constraint that requires the planning and scheduling platform to create an optimal schedule given the number of available drivers. However, when a radical service change is made, it may be better to first decide which services be cut (using weekend service or other cuts) and then deal with the driver absenteeism issue.

2. Scheduling implications: cutting span, frequency and coverage

Agencies and operators made service cuts across service span, frequency and coverage. The scheduling lesson here was that changing service metrics was easiest to do in systems where there was a seamless integration of the ability to visualize routes on a map, tie them into timetables that can be changed quickly and then sync with the crew and vehicle scheduling. Without this synchronization the ability to quickly generate scenarios and understand their scheduling implications was lost.

3. Scheduling implications: quickly modelling new preferences for driver safety

Disinfection and the need to prevent cross-contamination among drivers soon created changes in break preferences, changeovers and turnarounds. First, one needed to quickly understand the implications of making breaks longer for disinfection. Afterwards, more rules were changed, limiting changeovers so drivers don’t cross-infect and minimizing changeovers. Some operators even grouped drivers in different groups to limit possible contamination.

4. Scheduling implications: rosters

As mentioned above, many agencies took Saturday or Sunday schedules and formed weekly rosters of them. Using optimized rostering in this case can deliver on many fronts. It fairly allocates work amongst drivers as well as deals with the need to reduce roster counts to protect drivers or deal with absenteeism. Yet, the absence of optimization technology made this much harder. Although going for a weekend service was the easiest way to reduce service, both from the point of view of communicating with the public as well as scheduling ease, the lack of rostering modules made this difficult. That’s why the virus has driven a discussion of whether cafeteria style rostering should be abandoned for roster optimization.

5. Scheduling implications: collaboration and remote work

Last but not least, with the necessity of having as many people as possible work from home, the importance of cloud-native systems became evident. The use of an on-premise scheduling platform was difficult, and the ability of several schedulers to collaborate and train remotely on such systems became crucial.