Although personnel must be planned in each railway transportation mode, there are differences in the planning processes. A selection of relevant characteristics for freight and passenger railway transportation is summarized in Table 3.1. The latter is divided into long-distance, regional/suburban and urban transportation modes.
In passenger transportation, operational crew planning is based on a fixed timetable, i.e. fixed demand, and is therefore reviewed and adjusted on a (bi-) annual basis.
Pas-Table 3.1: Special characteristics of different railway transportation modes
very long very long medium short
senger transportation modes differ in their operated geographical distance and in the frequency of their services. Long-distance trains run on a monthly, weekly, daily or hourly basis depending on the country, the travel distance and the demand. Regional trains satisfy the travel demand of the daily life (e.g., commuting) and therefore run at least daily, rather hourly or even several times per hour. Urban railways serve the high travel demand in large cities and areas of dense population and, thus, typically operate on interval timetables (i.e. trains run at specific intervals, e.g. every 10 minutes). In contrast, freight transportation is to a significant extend last-minute business (J¨utte/
Thonemann (2012b)). At a large European freight railway carrier, 80% of all trains are regular trains with about 20% of these being canceled or changed at short notice. The
3.2 Crew planning in railway operations 31
remaining 20% are special trains which are scheduled only a few days before operation.
Therefore, the operational planning horizon is usually monthly to daily, because a con-siderable proportion of trains is integrated in the timetable a few days before operation (changes or short-term demand). Accordingly, transportation services and the associ-ated timetable can be either a combination of both regular and irregular or in some cases completely irregular (Kumar et al. (2009)).
The type and number of driving personnel also varies, not only depending on the trans-portation mode but also on the country in which the service is operated. While subways require only one or even no train driver (also referred to as engineer (American English) or engine driver (British English)) to operate the train, regional trains are often manned by a driver and a conductor. The latter is responsible for safe and efficient operations and passenger service by, among others, controlling tickets, making announcements and securing departure (Fuentes/Cadarso/Mar´ın (2015)). Recently, the demand for security guards to improve the safety of both passengers and personnel has been growing (Snijders/Saldanha (2017)). In long-distance services, crews consist of the driver, several conductors and the catering staff who operate the on-board restaurant or provide snacks at short notice. In freight transportation, the terms are similar, but the tasks are slightly different. The driver operates the train and the conductor is responsible for operational and safety activities (Balakrishnan/Kuo/Si (2016)). Some crew types and their terminology are specific per country: in the US freight transportation, for ex-ample, the driver is assisted by an assistant conductor (historically a brakeman to assist the braking of the train, Liu/Haghani/Toobaie (2010)). Other railway operation personnel has also been subject to scheduling studies, but are not part of this review (see Pour et al. (2017) and Wang/Gronalt/Sun (2017) for a study on maintenance crews and depot shunting driver, respectively).
The length of trips is also a major distinguishing feature of the individual transporta-tion modes. On average, a freight or long-distance trip is longer than in suburban and urban transportation, both spatially and temporally. A gradation can also be observed between suburban and urban traffic (medium vs. short average trip length). As a result, the number of trips per duty varies greatly. In urban and suburban transportation 20 or more trips are not uncommon. In contrast, a long-distance duty contains only few trips, e.g., 2 to 4 trips (Kohl (2003)). The main operating hours in passenger transporta-tion occur during day time with some operatransporta-tions during the night (e.g., night trains in long-distance or during the weekends in regional and sub-urban/urban transportation).
The workdays follow the structure of weekdays, hence, duties are typically planned on an one-workday basis. In contrast, freight transportation is usually operated 24/7 with no working day boundaries. A duty typically consists of an outbound trip from the crew
member’s home station to the away station, followed by a return trip from the away station to the home station (Balakrishnan/Kuo/Si (2016)). These characteristics also apply to some long-distance passenger transportation, especially in large countries with sparse railway networks. Therefore, a freight, and in some cases long-distance, duty can last two or more days accompanied by an overnight stay in a hotel. Accordingly, the number of possible duties in freight and long-distance transportation is rather medium (up to 100,000 per day, see Kohl (2003)), in suburban and urban transportation rather big (more than 1,000,000 per day possible, see Hoffmann (2017)).
Operators aim at using the trains of their transportation network for deadheading activities for cost reasons. However, this is not always possible since a duty might not end at a home depot and there is no train run available to bring the crew back. Such cases require special crew transport, mainly taxis, which increases the cost for deadheading.
In freight and long-distance transportation, deadheading time might be very long and therefore expensive. In this case, a layover in a hotel might be more cost-efficient. Since the range of regional and urban railway networks is relatively smaller, the time for deadheading is medium to short. In such cases, taxis are only used if there is no other possibility.