Navigant Research Blog

Denver RTD Hops on the Electric Bus Line

— October 3, 2017

Commitments to electric buses (e-buses) are ramping up in the United States. Several agencies are bringing in fleets of a few dozen to over 100 e-buses over the next few years. One such agency, the Regional Transportation District (RTD) of Denver, is deploying 36 e-buses from Chinese company BYD Motors, Inc. Among the biggest drivers for the interest in e-buses is their increased efficiency. These BYD buses are expected to get 12 MPGe to 14 MPGe, significantly improving on the 3-4 miles per gallon of diesel buses. E-buses also have reduced maintenance costs. RTD says the biggest maintenance issue with these buses are the doors.

BYD Bus Details

Each vehicle costs $750,000; this includes the price of the battery chargers and a lifetime warranty for the lithium iron phosphate batteries. Lithium iron phosphate batteries were chosen for two reasons: they are designed to prevent thermal runaway and the batteries are air-cooled to maintain a narrow range of temperatures.

The buses have a maximum battery capacity of 292 kWh that requires 3-4 hours of charging time, giving them 12-14 hours of continuous use before requiring a charge. This has been demonstrated to provide 200 miles of range at 30-40 mph. However, in operation, the range is closer to 80 miles because buses make frequent stops during the 1.3-mile route.

Incorporating E-Buses into the Fleet

Three-phase alternating current (AC) fast-charging stations were installed for the fleet. The AC-to-direct current (DC) converter is onboard the bus. The lack of fast-charging standards in the United States for heavy duty vehicle e-buses is a challenge, as buses must be coupled with proprietary standards. That being the case, RTD has opted to use European standards. The construction of the charging station cost $432,000; this figure does not include the cost of the battery charging equipment.

Because the new fleet is quieter than traditional buses, they have been outfitted with noise generators (that fluctuates pitch with the vehicle’s speed) to notify pedestrians of their presence when operating along the pedestrian-oriented 16th Street Mall. The buses were ordered in 2015 and manufactured in China; final assembly will take place in Lancaster, California to meet Buy America requirements. As of August 2017, 34 of 36 buses had been delivered. RTD has indicated it hopes to incorporate e-buses in regular operations in the future.

Although the e-bus rollout has been successful to date, RTD reports that few agencies have reached out for advice about implementing their own e-bus fleets. Nevertheless, transit agencies across the United States are taking a good look at e-buses.

Other Market Drivers

While lower operations and maintenance costs are already market drivers, there are other market drivers that will become more prominent and increase the desire for e-bus adoption. Dynamic charging systems would enable buses to carry smaller batteries, decreasing costs. In addition, vehicle automation is well-suited for EVs on fixed routes, including buses. Other market drivers include increasing cities’ targets for air quality and climate change concerns and increased demand for vehicles with a reduced carbon footprint. According to Navigant Research’s recent Market Data: Electric Drive Buses report, electric powertrain buses (including all types of hybrids) are expected to grow from approximately 21% of the total bus market in 2017 to around 22% in 2027.


Using Open Data to Close Mobility Gaps

— April 13, 2016

Mass rapid transitCan the open data movement help create better access to high-quality transportation services not just for the urban elite but also for the underserved? That’s what the U.S. Department of Transportation (DOT) is hoping will happen thanks to a new public transit data gathering initiative. In March, DOT Secretary Anthony Foxx announced that the agency is seeking to create a national transit map using transit route data from operators across the country.

Many U.S. transit agencies have already joined the open data movement, driven in part by the opportunity to have Google Maps provide users with transit travel options. A 2015 report by the U.S. Transit Cooperative Research Program (TCRP) on the state of open data in public transportation noted that between 2009 and 2012, many of the largest transit agencies in the United States created application programming interfaces (APIs) that third-party software developers can use to access real-time data feeds of bus and train location information. Many transit agencies have developed the GTFS (or General Transit Feed Specification) feeds that Google Maps uses to provide its transit directions.

National Snapshot

A new development is combining this data into a single map of transit in the United States. According to the DOT, its National Transit Map will provide a comprehensive, national snapshot of “where transit stops are, how frequent transit service is, and where transit routes go.” Note that this is all static information—this National Transit Map won’t take the place of real-time data used by smart phone app developers for individual transit systems. However, the DOT hopes that researchers and advocates will use the data to show where transit coverage is strong and where it is lacking. This is actually the kind of information that’s been available for years on U.S. roadways through the U.S. Federal Highway Administration (FHWA). The FHWA provides data on over 450,000 miles of U.S. highways that can be used to determine accessibility and usage rates.

The United States is joining just a handful of other countries that have open data on national public transportation services, rather than on a transit system level. The United Kingdom was one of the first countries to introduce a national public transportation database. The National Public Transport Data Repository captures every bus, train, and coach trip that occurs in the same week in October across the country. The repository has data from every year from 2004 to 2011, but has not been updated since 2011. When it was made public, the data was used for, among other things, an analysis of which parts of the country lagged in bus service. Sweden’s TrafikLab provides data on the country’s public transport systems. In Germany, transit data was pulled together by a group of activists, rather than the government.

Untapped Potential

There is still tremendous untapped potential in the data on transit services available to the wider public. The U.S. effort to collate this data and make it easy to access is an admirable step in this direction. While DOT secretary Foxx has expressly said his goal is to close the transit access gap, unstated is how this would occur. Presumably through encouraging additional investments in traditional public transit systems, but it would be an interesting exercise to overlay the transit coverage to data on shared mobility options. This data is largely held by private companies, however. There have been some initiatives to let cities access ride-hailing data, such as Uber’s partnership with Boston, but it is likely to be very difficult to access most of this information at a larger scale.


In Korea, Wireless Charging Takes the Bus

— August 29, 2013

Wireless charging is a technology that attracts more public attention than its actual use would seem to warrant.  This week saw breathless reports that the Droid 5 might include wireless charging capability and GM plans to put a wireless charging mat into its 2014 models for mobile devices.  In the electric vehicle (EV) market, Bosch introduced the first aftermarket wireless charger for EVs in the United States during July, the Plugless charging system.

In some ways, EV wireless charging seems superfluous.  We already have good charging technology: the plug and cord.  It works, it’s safe, it’s easy to use, and it’s affordable.  It seems counterintuitive to replace that with more expensive technology when you’ve got a market already limited by high prices for the cars themselves – unless that extra cost gives you some significantly higher utility.  As we have discussed earlier, developers argue that wireless charging can be a market enabler for EVs – by upending the range versus charging time dilemma.  EVs would be charged frequently, throughout the day, allowing OEMs to downsize the battery without sacrificing performance.  Once the initial investment in wireless capability has been made, adding new charge pads would be cheaper than adding more charging boxes.  But, as noted in the Navigant Research report Wireless Charging Systems for Electric Vehicles, it will likely take many years for the plug-in EV (PEV) market to make this shift.

A new demonstration project in Korea presents another angle in the wireless charging argument.  The Korea Advanced Institute of Science and Technology (KAIST) is running two electric buses equipped for wireless charging … while operating.  KAIST engineers built a 7.5-mile charging mat on a 15-mile transit route at a cost of $4 million.  The two buses reportedly have batteries that are just one-third the size of a regular electric car battery.

In this case, the argument is that wireless charging can extend the effective range of battery buses while lowering the cost of the buses, since they use smaller batteries.  Range and cost are serious limitations for battery buses, more so than in the passenger car market.  As forecast in Navigant Research’s report, Electric Drive Buses, battery buses will constitute well under 1% of transit bus sales for the next several years, with sales in the thousands from 2014 on.  Key reasons for this are the higher price, lower passenger capacity, and reduced range, all of which limit the utility of battery buses for transit operators.

Annual Battery Electric Bus Sales by Region, World Markets: 2012-2018 Lisa's blog C7.5

(Source: Navigant Research)

In effect, the KAIST wireless system would be like having a light rail or trolley line, only without the overhead lines that many consider an eyesore.  The drawback is that the wireless charging equipped bus is tied to an exact route.  The transit operator loses the flexibility that a battery bus can provide, compared to a trolley or light rail system.  For the near term, the best application may be on well-established transit routes that are not likely to shift over time – for example, routes in urban centers where cities want to reduce emissions and noise, such as downtown malls.  The technology may eventually be incorporated in the planning process for new roadways, allowing widespread deployment of the wireless charging that would give transit operators more flexibility in designing routes.  But this seems a long way off.  In the meantime, KAIST says it will add 10 more buses to the route in 2015, if this first trial is a success.


Dublin Digs Deep with City Data

— June 24, 2013

Cities that want to take advantage of new technologies to improve their operations should be ready to embrace both top-down investment in new management and control systems and bottom-up innovation from a wide range of stakeholders.  Dublin provides a good example of a city that is taking advantage of both approaches to attack some critical city issues.

The Irish capital faced a serious congestion problem as its economy boomed before the credit crunch.  Some estimates suggested that congestion was costing the economy over 4% of GDP.   While the economic downturn has eased the pressure on the traffic system in the short term, the city realizes it has to get smarter at dealing with the underlying problems.

The city’s transportation managers have been working with IBM’s Smarter Cities Technology Center, which is based in Dublin, to understand how they can use data analytics to help optimize traffic management and improve the operation of the city’s bus system. Dublin has no metro, so the bus system is particularly important for transportation in the city.

Working with the IBM research team, the traffic department has combined data from bus timetables, traffic sensors, CCTV and real-time GPS updates for the city’s fleet of 1,000 buses.  This data is used to build a digital map of the city, overlain with the real-time position of each Dublin bus. This allows traffic controllers to see the status of the whole network, drill down into problem areas and make informed decisions on the best actions to reduce congestion.  The data also enables better optimization of traffic management measures and of the bus schedule.

The SPUD Effect

I spoke to Brendan O’Brien, Head of Technical Services, Roads and Traffic Department at Dublin City Council, about the impact of the system at an IBM-hosted event in the city in May.  I asked him how this data had changed the city’s approach to managing the city’s transport.  O’Brien said his team can now combine macro and micro levels of management much better, viewing problems in specific locations while also developing better informed strategic plans for the city.  The challenge is to find time to take advantage of these strategic insights.

Dublin is not only looking to the city’s control systems and big data analytics to improve insight into traffic and transport conditions, but also at the possibilities offered by open data. Dublinked, the city’s open data platform, provides an impressive range of public data sets and enables third parties and individuals to contribute data.  Dublin City Council and other local authorities in the Dublin region are working with the National University of Ireland Maynooth to explore the opportunities for service innovation and collaboration with other agencies and suppliers. Mapping of disabled parking spaces in the city, for example, has been done through crowdsourced information.  IBM has also been using the data to demonstrate the possibilities for data analytics on open data platforms with its Semantic Processing of Urban Data (SPUD) demonstration.

Dublin is a good example of how a smart city strategy should not depend on any single system or application, but rather on the innovative use of multiple tools and applications, shared data, and collaborative networks for innovation.


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