How much money do buses waste when they idle at the station?

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If you often take public transport, you probably don’t think twice about popping in your earphones during your commute. Crowded places can get pretty noisy, and that’s understandable. But just the other day, while waiting for the bus at the Kelana Jaya station, this writer realized something that she never really thought to question…

Did you guys know that our public buses leave their engines running while they’re parked at the bus hub? And it’s not just a couple of minutes of idling either, we’re talking a full hour here! As in multiple buses, all grouped together with no one inside, just churning out all that noise and smelly exhaust smoke 😩

With all that racket we could hardly hear ourselves think. But even so, there was one question we couldn’t get out of our heads: Just how much of a waste is it to let those engines run like that?

The financial costs can add up to seven figures!

Okay, so here are some quick facts:

Our public transport system is 100% government owned.
Subsidised diesel price (which includes public transport) is RM 2.15 per liter. But since the government bears the cost of subsidy AND owns the public transport system, we’ll be looking at the market price of diesel which is RM3.75 per liter.
The average heavy duty diesel engine burns 3.03 liters of diesel while it’s parked and running.

So here’s the math: diesel costs RM 3.75 per liter and idling buses burn 3.03 liters per hour. Multiply those together, and you get RM 11.36 wasted every hour a bus leaves its engine running. This might sound like pocket change, but think about the number of buses running daily and how often they idle. In 2019, Prasarana (the people who run our public transport) reported a total of 1853 buses in their fleet.

Even with modest estimates, we’re looking at thousands of ringgit lost every day. Over a year, that’s hundreds of thousands, maybe even millions of ringgit up in smoke!

But now that you know how much they waste, you might wonder why? Aside from the costs, there’s all that air pollution, noise pollution, and a bunch of other headaches an idling engine brings. If it were your own car, you’d never let it run like that, knowing the impact and expense.

Well, here’s the thing…

Sometimes it’s really tough to restart these buses once they’re turned off

So in between our moments of spying and covert video shots (here’s another one btw showing the bus idling about 22 minutes before it’s meant to depart)…

…we did also talk to several bus drivers asking why the leave their buses running.

The main reason seems to be that it’s difficult to restart the bus once the engine cools down. We found a couple of corresponding sources for this, though they’re mostly forums. Essentially, diesel engines take long to warm up, so it’s simpler to keep them running than to risk a ‘cold jump’.

The Pak Cik Bus Driver also brought up the fact it takes at least 5 minutes for the bus to isi angin. You see, buses operate on an air brake system, and when they start up, that air needs time to pressurise before the brakes can even work.

“Sure it’s a waste of money to keep the engine running, but when the break between bus trips are only 20 minutes long, it’s not convenient to turn off the engine when you need to restart, warm it up, then wait till the air is ready,”– Nice Pak Cik Bus Driver #1

An air gauge on the bus dashboard. Screenshot from Puspakom

At another stop, a different Pak Cik Bus Driver spilled a little secret. Keeping the bus running means the air conditioning stays ice-cold, which ensures everyone smells as fresh as a daisy when they disembark.

“Sometimes passengers complain it’s too hot, especially in the afternoon, so we just leave the engine on for the aircond,”– Nice Pak Cik Bus Driver #2

Well, well, well, guess who immediately felt grateful to the bus drivers for their kind consideration? (Yep, this writer 🙋🏼‍♀️). All the same, some of you might still feel tak puas hati about these idling buses, especially when you have to sit next to their hot, smelly, noisy engines for extended periods of time. But things may not stay this way for long because…

The government is already moving towards cleaner energy

Did you guys know that Malaysia has officially stopped buying diesel-fueled buses? The last batch of orders is expected to arrive in 2025 and after that, Transport Minister Anthony Loke says we’re making the switch to electric buses.

“Prasarana has set a target to phase out diesel buses by 2037. Between 2025 to 2030, the corporation said it wants to add over 1,100 electric buses,”– excerpt from Malaymail

The new buses that are already running on the BRT Sunway line

This is all part of Malaysia’s big push to go green, as you guys may have noticed with all the buzz about EVs that’s been happening lately. But ofc, the transition to a full-fledged sustainable system will take some time (a little over a decade if we wanna be exact), so you might still have to marinate in a bit of smoke while waiting at the bus stop for a while.

But hey, better that than marinating in sweat, right?