Kotoden operates a pattern timetable on all three lines.
Kotohira Line
A regular half-hourly service operates all day between Kotohira and Takamatsu-Chikkō (6.00 - 22.00 from Takamatsu-Chikkō and 5.42 - 21.12 from Kotohira). The travel time is 61 minutes each way. With an 11-minute turnaround time in Kotohira and 17 minutes and in Takamatsu-Chikkō, one trainset needs 2,5 hours to make the round trip, which means there are five trainsets needed to run the half-hourly service.
During the daytime, there is an additional half-hourly service between Ichinomiya and Takamatsu-Chikkō. This daytime service has a 21-22 minute travel time, with a turnaround time of less than a minute in Ichinomiya and 17 minutes in Takamatsu-Chikkō, meaning one trainset would need one hour to make the round trip. However, when both services are running, the trains can make a 2-minute turnaround in Takamatsu-Chikkō (the train coming in from Ichinomiya goes back as a Kotohira service and vice versa). This saves one trainset, so that there are six trainsets needed for the daytime service.
During the morning and evening peak hours (roughly between 6.00 - 8.00 and 18.00 - 20.00), the Ichinomiya service is extended to Takinomiya. The travel time of the Takinomiya service is 41 minutes each way. With a 21-minute turnaround time in Takinomiya, there are eight trainsets needed for the peak hour service.
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During the busiest morning peak (roughly between 7.45 and 8.45) there is an additional 15-minute service between Busshozan and Takamatsu-Chikkō, with the round trip taking 45 minutes, which would mean three additional trainsets needed, but here again, Kotoden made an optimised schedule: the 7.45 outbound Takinomiya service ends in Ichinomiya and this trainset is used for the inbound Busshozan service. In total the full peak service is operated with ten trainsets.
The variation in peak vs. off-peak demand/frequencies is also used in a smart way to get the trains in and out of their respective depots, so that very little empty runs are needed. Four trainsets start and end in Kotohira, two in Takinomiya and another four at the main depot, located at Busshozan station. Basically, all services are operated with two cars, but during the peak hours, most trains are operated with four cars. The lengthening/shortening of the trains is done in Busshozan.
Nagao Line
The basic interval on the Nagao Line is 24 minutes. During peak hours, the frequency is doubled, giving a 12-minute interval. The travel time is around 40 minutes, with a turnaround time of 8 minutes in Takamatsu-Chikko and 6 minutes in Nagao, resulting in a round trip of 96 minutes. This means 8 trainsets are needed for the peak hour service.
Basically, all trains run end to end, but shorter workings (starting/ending in Hiragi or Kawaramachi) are used to get the trains in and out of the depots. Three trains start and end in Nagao, three trains in Kawaramachi and one train in Hiragi. The eighth trainset starts/ends in Takamatsu-Chikkō (empty running from/to the main Busshozan depot for cleaning/maintenance). All trains run in a two-car formation.
Shido Line
The basic interval on the Shido Line is 24 minutes. This interval is the same as on the Nagao Line, allowing for good connections between the two lines in Kawaramachi. Unfortunately, the timetables of both lines do not share the same symmetry minute. Therefore, a good connection (4–6 minutes changing time) is only provided from Shido to Takamatsu-Chikkō. In the other direction, long waiting times occur during the off-peak periods. The travel time on the Shido line is around 38 minutes, with a turnaround time of 16 minutes in Kawaramachi and 3 minutes in Nagao, resulting in a round trip of 96 minutes. This means four trainsets are needed for the basic service.
During the busiest morning peak, three additional train pairs are added between Kawaramachi and Omachi, reducing the interval on that section to 12 minutes. With a running time of 26 minutes and a turnaround time of 3 minutes in Omachi, it is not possible to do the return trip within 48 minutes. Nevertheless, this service can run with only two extra trainsets, because a short turnaround of 4 minutes is possible in Kawaramachi when both services are running. In total, the peak service is operated with six trainsets.
Except for the extra peak hour services, all trains run end to end. Two trains start in Shido and four trains in Kawaramachi (Imabashi depot). All trains run in a two-car formation.
