SBS bus #179 love to overtake "slower" NTU shuttle buses

Waiting for SBS 179 bus can test patience. Sometimes, you wait for >10 min just to find two of these buses tailgating one another, with seats (or occupancy) half empty. This scenario of course, happens off peak. That is why you get to wait longer for a bus at NTU. I wonder why there isn't strict enforcement of standardized timing for buses to start and end at a station. It seemed that there are some drivers eager to finish his shift faster, hence the haste to finish the journey, and resulting in two to three buses tailgating one another.

Back to the topic, some drivers of SBS 179 seemed eager to overtake "slower" NTU shuttles. This poses few concerns, mainly safety as the road around NTU is not meant for overtaking. Second, by overtaking shuttle, especially at bus stops (while the shuttle is stationery), SBS drivers often miss out few patrons waiting at these stops. For the drivers convenience (i.e. driving in front of slower vehicles), they are causing inconveniences to patrons who might have waited for the bus for ages.

Is fuel price getting low these days? Why the waste of dispensing buses just to get them back to base half/quarter utilized? How to change drivers mentality? How to implement/enforce simple rule?

I'm not paid to solve this problem. Get someone under SBS payroll to do it. My opinion is, SBS service is not getting any better.