When electric buses make sense, and when they just don’t
In a previous article, I mentioned the Albuquerque Rapid Transit (ART), a Bus Rapid Transit (BRT) system that entered the city a few years ago. Like many, I was disappointed that they replaced some supposedly problematic electric buses they had bought from BYD with “clean diesel” articulated buses. Solving their issues with BYD or moving to another electric bus maker seemed like the right way to deal with it, and switching to diesel… not so much.
What I didn’t know at the time was that electric buses aren’t always the best solution for public transportation. Yes, electric buses are definitely better than a diesel or natural gas bus. This is indisputable without seriously distorting the facts. The point is, combustion buses aren’t the only competition from electric buses, and in many situations even cleaner options are the answer.
How light rail is better than an electric bus (in some situations)
What’s an even better option? Light Rail. This video explores many reasons why a light rail system is generally better than the BRT.
The biggest advantage of using the rail is that you don’t have to deal with the rolling resistance of a vehicle with tires. Pushing soft, partially slippery tires requires much more energy than “steel-on-steel” rail vehicles. There is almost no warping and no real slippage, so the light rail uses much less electricity than an electric bus to get around.
Maintenance isn’t as important with an electric bus, so the light rail doesn’t beat them as much in this regard. But, over time, the cost of replacing a battery is something that a light rail system just doesn’t have to deal with. Because they get their electricity from overhead cables or an electrified third rail, most light rail systems do not need a large battery bank. The few who tend to use the batteries for regenerative braking or continue to ride short sections where electricity will not be available, but in these cases the batteries will be much smaller and easier to replace at the moment. came.
Light rail systems are also very flexible in terms of capacity. If there are too many people on a route, the only option is to add more buses, and with those buses the total cost of each additional bus that runs on the line. The light rail simply adds another section of train to the vehicle, and the overall capacity of the vehicle can be changed seasonally or even hourly to better match ridership.
Cost is the big area where an electric bus and a light rail can be competitive. The cost of laying the rails, building the stations and laying cables or third rails, and everything in between, makes the rail infrastructure much heavier than a bus. The bus can just hit the road and drive where everyone else is driving, so the upfront costs are much lower.
The great decision maker: How much of the route is like a train?
Routes like the Albuquerque BRT system illustrate how the decision to go by train or bus depends on this issue. ART has dedicated lanes, stations with bus-level platforms to speed up the loading and unloading of passengers, and other features that make it a train on tires. Sure, he’s rolling on the sidewalk, but it’s different enough that they have to create public service announcements showing an armed state agent telling you not to drive where he’s driving, or to face it. at the risk of a ticket or accident.
This is a perfect example of a situation where the light rail would make more sense. It is a fixed route with a lot of infrastructure, just like a train. The upfront costs would be a bit higher, as you would want to keep cars completely out of the lanes between intersections (as ART honestly should have done), but the cost of the platforms is something that is common to BRT and the metro. light. Additionally, the maintenance of diesel buses is going to be much more expensive over time than the cost of laying rails and cables would have cost for that fixed route.
Trams, trolleys and other smaller rail systems do not require dedicated platforms or tracks in most cases, so rail is also a better option for fixed routes without this infrastructure. They don’t share all of the advantages of light rail, because you can’t just add more cars to the train, but they don’t have rolling resistance or big battery packs.
Where rail doesn’t make sense is when the routes are not fixed. Some cities need the added flexibility of a wheeled vehicle that can travel on any lane of traffic, as they can change routes quickly with only signage changes. Or, more often, needs may differ in some cities on a seasonal or even daily basis. Places like a college town may reduce or eliminate parts of a route altogether at different times of the year, and then switch to new routes when the summer is over.
Thus, the more fixed a route, the more the rail is the answer. The less fixed and flexible a public transport system has to be, the more an electric bus becomes the big winner, despite the costs, because constantly laying a new rail and demolishing it makes no sense. This means that BRT systems like ART make no sense, because they look so much like a train, they might as well be a train.
Which makes even less sense
In this article, I have only explored when an electric bus or an electric streetcar or streetcar system might make more sense. What I haven’t explored is the place of diesel buses in this table.
The answer? They just don’t fit anywhere on the chart in 2021 and haven’t fit since about 2015. Cities that buy combustion buses are turning out to be the worst of all worlds with their tax dollars. They get the least efficient vehicle with the least efficient engine, with the highest maintenance costs. These quickly exceed the costs of electrical systems of any kind.
Whether a city adopts electric buses or streetcars doesn’t matter as much as preventing them from being dumb and buying combustion vehicles for public transport today.
Featured Image: Screenshot of one of the YouTube videos embedded in this article.
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