Time distribution ratios for train services

Abstract

In this paper, several time-distribution aspects are investigated. From available patronage data (Metrorail Census, Gautrain, BRT patronage, and Household Travel Surveys), ratios are determined for peak period and busiest peak hour (both AM and PM), and off-peak compared to an average workday, as well as for weekend days.

The pre-determined peak periods are often set at 06:00–09:00 and 16:00–19:00. However, it is found that the actual peak periods are often earlier. Additionally, due to daylight times, the actual peak periods in Cape Town are approximately half an hour later than in Durban.

The patronage ratio for the 3-hour peak period (and top hour) is 40% (and 20%) of the workday total for Metrorail, and 35% (and 15%) for Gautrain. The PM peaks are slightly lower than the AM peaks.

A decent off-peak service frequency will result in relatively higher off-peak ratios, at 20-25% of the workday in the 7-hour off-peak period. However, with a poor service frequency, the off-peak period is below 15%, and subsequently the peak ratios are higher.

These ratios can assist in designing public transport and train corridor operations, where the peak demand determines the required capacity and most of the operational costs, and the daily plus weekend patronage determines the passengers’ revenue. A higher off-peak and weekend ratio will result in a better use of operational assets and improves the financial viability of the system.