Expanding the Bus Service Reliability Trial

News Releases
5 Jun 2015

Number of Trial Services to Be Doubled to 45

1.  23 bus services[1] will be added to the Bus Service Reliability Framework (BSRF) trial by the end of this year, increasing the total number of services on trial to 45. In addition, a new indicator, On-Time Adherence (OTA), which measures the punctuality of bus services, will be trialed for two low frequency services[2]. The BSRF trial will be extended until August 2016.

The Bus Service Reliability Trial

2.  The BSRF was introduced in February 2014 to improve the regularity of bus arrivals and reduce bus bunching. The first assessment period of June 2014 to November 2014 had yielded promising results. 20 out of the 22 services on trial had improved their reliability.

Expansion of the trial by 23 services

3.  Given the encouraging results for the original 22 services under the trial and LTA’s intention to include all public bus services under the BSRF in 2016, LTA has worked with the Public Transport Operators to expand the trial by 23 services; 12 services in June and 11 in December 2015. This includes a mix of long and short trunk routes, as well as feeder services, spread across the island. The 23 new services will be assessed against a tighter baseline than the original 22 services, taking into account the improvements made in the first year of the trial.

New performance indicator introduced for low frequency services

4.  For high frequency services with headways of 15 minutes or less, where commuters generally do not refer to a timetable, the regularity of a bus service is adequately assessed using Excess Wait Time (EWT), which is the average additional wait time experienced by commuters at bus stops compared to the expected wait time[3].

5.  For bus services with lower frequencies, where headways are generally more than 15 minutes, adherence to arrival timetables is more pertinent. Thus, LTA will introduce a new indicator, the On-Time Adherence (OTA), which is the percentage of on-time arrivals at selected bus stops.

6.  For a start, from December 2015, LTA will trial two low-frequency services (SBST Bus Service 115 and SMRT Bus Service 927). The timetables of these two services can be found on the respective bus operators’ websites. A bus arriving at a bus stop is considered on time if it is no more than two minutes early and no more than five minutes late[4]. Buses are required to be on time for at least 85%[5] of arrivals daily. To qualify for incentives, bus services must have more than 87% of trips arriving on time. Conversely, bus services are penalised for less than 83% of trips arriving on time.

7.  The introduction of the OTA as part of the BSRF trial will allow LTA to trial and make refinements to the indicator, before introducing it more widely to other low frequency services as part of the bus contracts.

Extension of the trial to end-August 2016

8.  LTA will bring all bus services under the BSRF from the second half of 2016 with the transition to bus contracting. LTA will therefore be extending the trial from February 2016 to end-August 2016 such that there is no gap in implementing the framework.

Annex A:
Baseline EWT and OTA indicators for services added to the BSRF trial

[1] Services to be added in June 2015: SBST Bus Services 58, 63, 76, 130, 163, 175, and SMRT Bus Services 171, 180, 851, 857, 882 and 975.

Services to be added in December 2015: SBST Bus Services 28, 65, 101, 115, 155, 261, 315, and SMRT Bus Services 187, 800, 927 and 965.

[2] SBST Bus Service 115 and SMRT Bus Service 927.

[3] The EWT will be zero if a bus service arrives with perfect regularity according to schedule. However, if there is bus bunching, resulting in a prolonged wait for the next bus, the EWT will increase.

[4] We have adopted a stricter window for buses that arrive earlier than scheduled as the adverse impact on commuters is greater. Commuters who miss such a bus would have to wait a longer time for the next bus, compared to commuters who are waiting for a bus which arrives later than scheduled.

[5] The OTA standard has been set with reference to international benchmarks, for instance, London.