Fun history note: the old service 4 (which absorbed the 2nd generation 19) was only amended to Tampines in 1992, mainly due to the introduction of service 21. Service 4 was already on its way out due to its route running parallel to the EWL between Pasir Ris and Kallang, but it still had some very good sectors that needed to be covered. 21 would be extended from Geylang Lorong 1 to St Michael's to cover for 4 between St. Michael's and Geylang (while already covering its Pasir Ris sectors since introduction), while 67 took over the sectors between Tampines and Lavender Street (originally, 67 was a semi-express route in the East, plying the PIE between Tampines Ave 5 and Bendemeer/Serangoon Road).
So it had to split service 4. Service 21 is primarily Pasir Ris - St Michael's, which had to serve the newer HDB estates in Bedok Reservoir and Eunos. 23: Cut to Rochor Canal Road 67: Amend to replace service 4 but still need to parallel to EWL and DTL and avoid duplicating service 23. It replaced service 172 too.
![[全区間前面展望] SBS Bus Service 59 (1988 - 1992年) Jalan Kayu Bus Terminal - Bishan Bus Interchange](http://i.ytimg.com/vi/t6aP92Dtdxc/mqdefault.jpg)
![[全区間前面展望] SBS Bus Service 59 (1988 - 1992年) Jalan Kayu Bus Terminal - Bishan Bus Interchange](/img/tr.png)
Fun history note: the old service 4 (which absorbed the 2nd generation 19) was only amended to Tampines in 1992, mainly due to the introduction of service 21. Service 4 was already on its way out due to its route running parallel to the EWL between Pasir Ris and Kallang, but it still had some very good sectors that needed to be covered. 21 would be extended from Geylang Lorong 1 to St Michael's to cover for 4 between St. Michael's and Geylang (while already covering its Pasir Ris sectors since introduction), while 67 took over the sectors between Tampines and Lavender Street (originally, 67 was a semi-express route in the East, plying the PIE between Tampines Ave 5 and Bendemeer/Serangoon Road).
So it had to split service 4.
Service 21 is primarily Pasir Ris - St Michael's, which had to serve the newer HDB estates in Bedok Reservoir and Eunos.
23: Cut to Rochor Canal Road
67: Amend to replace service 4 but still need to parallel to EWL and DTL and avoid duplicating service 23. It replaced service 172 too.
hmm what is zbk doing in my area