It’s been almost a year now that we’ve looked back and explored some of the classic makes and models of motor coach transportation in North America. And thanks to others such as our good friend Johannes Dutch, we’ve also been enlightened with in-depth and informative articles on coaches from Europe and other areas. There are still plenty of classic older buses to highlight, but Jim Klein’s superb overview of his recent trip on the “Bustang” made me think that it might be a good time for a look ahead, rather than the past. So let’s see what may be in store for bus riders in the next several decades.
Our first trend attempts to leverage all the benefits of light rail, without the single main disadvantage – cost. Bus Rapid Transit (BRT) is becoming ever-more popular and uses large, high passenger-load coaches, designated lanes, automated right of way at intersections, elevated stations that allow for platform level entry, and off-board fare collection – all to make the bus riding experience more enjoyable, easier, and quicker.
It is growing in popularity – and as Paul has commented on, has even spread to our founder’s bucolic hometown, Eugene Oregon.
Buses are typically articulated models, usually with two sections, though sometimes more. Currently, most use diesel power, though as we’ll see below, other options are catching on…
BRT seems to work best when a comprehensive transportation system is already in place to feed passengers into the BRT corridor. Without that, ridership can sometimes fall below projected levels. But because it can use existing roadways reconfigured for bus lanes, it is significantly cheaper than light rail. We’ll likely see it continuing to expand in the future…
Other future trends are related to power trains. Currently, clean diesel and compressed natural gas (CNG) are the two major fuels used to power buses. In the US today, about four-fifths of new transit capital purchases are diesel, the remaining fifth CNG. But both emit some emissions, and with ever tightening government standards, other technologies are being brought to the forefront. One in small-scale test and evaluation since the mid-2000s is hydrogen fuel cells. Fuel cells take hydrogen, stored in on-board cylinders, and run it through a converter which separates the atoms through electrolysis, sending electricity to batteries and motors, with water as the other byproduct.
Fuel cells have several advantages; the system provides more energy at the driven wheel than an equivalent diesel-engined bus. Moreover, it’s a true zero emissions solution – the only thing that comes out of the tail pipe is water. It also provides a range similar to diesel – about 200-250 miles between hydrogen refills.
But there are some significant limitations; the biggest being expense. Fuel cell technology itself is costly, as is the infrastructure to sustain it. Based on a study by California-based AC Transit in 2010, cost of operating a diesel fleet was less than half (41%) of one with fuel cell coaches. Most of this cost was in building the hydrogen delivery and storage infrastructure, but the coaches themselves were also more expensive to acquire and maintain. A variety of companies and cooperatives, with government support, are working to advance this technology and bring these costs down.
One such company is Toyota – which as I’m sure readers here know, began marketing its Mirai fuel cell sedan in the US in 2015, and in other markets this year.
Toyota also recently debuted a new fuel cell bus – not surprising as its Hino subsidiary has been experimenting with large fuel cell coaches, showing one at the 2015 Tokyo Motor Show.
The other major power train trend is battery-electric propulsion. Battery-electric buses face the same two hurdles as all vehicles with this motive power; range and recharging cycle time. As we’ve seen with Tesla, over the past twenty years, battery capacity and recharging options have seen steady incremental improvements. A typical electric bus today has about a 170 mile range between a full and non-usable charge – the BYD “Lancaster” bus above, showcased at the 2015 American Public Transportation Association (APTA) Expo in Houston, is an example.
The key variable however is recharging cycle time – today, there are two general methods being evaluated that will provide for rapid charging of urban transit buses (versus taking a coach out of service for a long, 4-6 hour recharge). First is inductive or wireless charging. Here, inductive coils or wires are implanted into roadways or at specific quick charge stations and buses receive a charge wirelessly, without any direct connection. This system shows promise, but currently the transfer rate is still fairly low.
The other, more promising method, is for buses to receive a quick charge from an overhead charging station via catenary wires or a pantograph. Both Siemens, the large German-based industrial conglomerate, and Opbrid, a Spanish company, are testing new high-powered pantograph charging systems that provide a 90% recharge in 3-5 minutes. Such a system may work well at terminal end points where these short recharging layovers can be factored in to the overall route schedule.
I’ll offer a prognostication – my guess is barring some breakthrough in clean diesel/CNG technology or hydrogen delivery and storage, battery-electric will become the primary motive option for future urban transit buses.
Time marches on…