Tuesday, 22 May 2012

Fuel Savings Beyond Idling


The above link talks about the city's push to reduce idling and save on diesel costs at OC Transpo.

Coolant Heaters. I'm hard pressed to believe that the practice of running buses overnight will ever cease at our garages. What is seldom mentioned when suggesting solutions such as having maintenance staff start the buses an hour before they are due to leave for the day is the simple fact that 300 buses take longer than a few minutes to start. It takes hours to start "the fleet". It is such a huge oversight that the city didn't spec their buses out with devices that heat the coolant overnight instead of running their main engines overnight. ProHeat is a great example. I never bought a truck without one. Saves thousands.

But what factors save fuel beyond idling?

Maintenance is a big factor. Tire pressures, wheel alignment, air filters, evaporative systems... all huge factors in fuel consumption, but I believe that OC's fleet is pretty much as good as it can be in this department.

Driving behaviour. When the first set of articulated buses came in from New Flyer, drivers hated them. The fuel map programming was such that the buses would run at idle torque until the bus reached 10 kph, and only then would the engine begin to rev up. This was computer controlled, but that didn't stop drivers from blaming everything from displacement to defect. The logic is simple, however. Slowing the rate of acceleration through the first 10 kph should save fuel. The only problem with having that kind of behaviour under the control of a microchip is the fact that some buses couldn't make it through a traffic light without the light changing. That kind of behaviour can, however, be coached into a driver's repertoire. The city now gives drivers a "Smart Driver" program aimed at fuel savings. As I have stated ad nauseam, without access to data on daily fuel consumption via a trip computer located on the dashboard, the training simply doesn't pay off for the driver.

Speed limits. The Transitway has many zones in which a bus must be "floored" to the speed limit, only to be stopped almost immediately for the next stop. St. Laurent station to Train comes to mind. It is a huge waste of fuel to try and break 80kph along this stretch, yet hundreds of buses do it daily. There are other examples throughout the Transitway, but I'll let that go. I too, like to get you home ASAP.

Flag placement. Why place a bus stop across an intersection from a stop sign? If a bus must stop at a stop sign, or possibly stop at a traffic light, put the bus stop there! A great example of this is Des Epinettes ave just east of Prestwick dr. (2423) There are 58 daily buses scheduled to stop at this flag (according to the main schedule). All 58 of these buses must stop at the stop sign first, then cross the intersection and stop again at the flag 75 feet past the stop sign. That is only one flag, on one street... but we are looking at 58 daily stops, 34 on Saturday, and 25 on Sunday for a weekly total of 118 scheduled stops. 6136 stops in a year that could have been avoided by placing the bus stop at the red octagon where the bus has to stop anyway. As an aside, the bus will do this again later in the route 200 feet before the stop sign at Orchardview, and then again 100 feet after the stop sign at Orchardview. Stopping and starting is the single most fuel consuming activity a bus can participate in. Reduce stops, consume less fuel. Period.

Deadheading. Are we ever going to reach the point where we test out the concept of the rail system we are implementing? You're thinking... what does this have to do with saving fuel, right? The train will cross the downtown core, and do the majority of the heavy lifting though downtown Ottawa. You will take a bus to Blair, hop on the train, and go downtown. Well, what if we did this with buses right now? Could we cut out the majority of deadheading buses by leaving rush hour buses in east, west and south zones, with only one line crossing the core? Cancel duplicate local service during the rush hour, let the express buses cover that service. Let them run between Blair and Orleans, Lebreton and Kanata, Hurdman and South Ottawa.  That is what the train will be doing in a few years, anyway! The core wouldn't be such a rush-hour parking lot without a bazillion unique routes and deadheading express buses all cluttering their way through it. The big myth about LRT is that it is faster because of capacity and grade separation. We are already sending more than enough buses through in a segregated lane. The real problem has always been the buses making multiple stops for a browsing public. Too much selection! Send ONE line across the core, people will jump on the first thing smoking, doors will close, and the line will move like it does in the morning (same people, no browsing in the morning, right?) Let the browsing be done at Hurdman, or Blair, or Lebreton... when the entire lot of them can get on at once. Deadheading would be a local phenomenon, instead of a trek to the other side of the city.

If you have ideas on any of this, post them in the comments section.

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