Can 3D Road Geometry Save Gas?

Intermap and an Auburn University research team study fuel economy in the heavy trucking industries.

Richard Bishop, the owner of Bishop Consulting, wants the gas-guzzling monsters on the road to think for themselves. To be precise, he wants them to think about their own fuel consumption. He and his peers believe vehicles can make sound decisions about fuel usage if they’re properly apprised of the terrain conditions ahead. For the fuel-driven trucking industry, this kind of research has widespread implications.

The main focus of Bishop’s consultancy is intelligent vehicles. His client list includes BMW, Mercedes Benz, Foster-Miller, the Federal Transit Administration, and the UK Highways Agency, to name but a few. To this list, he also adds Intermap Technologies, whose business revolves around collecting and marketing 3D road geometry. In early August, the company earmarked a grant for Auburn University to find ways to save fuel using its 3D GIS data.

The Road Ahead
“Around this time last year, I came upon some early research that had been done in Europe on predictive powertrain,” Bishop recalled. “[The study explores] how a vehicle can shift its gear and use its transmission mechanism to accommodate for the uphill climbs or the downhill slopes.” From this premise, it took only a small logical leap to reach the fuel-consumption potentials this application could offer, Bishop reflected.

The Intermap-sponsored research at Auburn University is aimed at “achieving simulation results and designing a predictive cruise controller and automatic gear shifting algorithm to calculate optimal vehicle speed and gear selection that improve fuel economy and operating costs,” according to the announcement.

The 3% Solution
David Bevly, head of the Auburn research team, bravely took on the task of explaining the digital modeling process in layman’s terms: “We have Intermap’s 3D road geometry. To investigate fuel consumption, we build the model of a typical truck’s powertrain operations. Then we feed the road conditions into it. We already know the truck’s dimensions, so when we combine those with the 3D road geometry, we get a longitudinal dynamic model [showing the forces resulting from the road slopes]. Then we run the model to determine its fuel consumption.”

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With a grant from Intermap, an Auburn University research team headed by David Bevly is looking into using 3D road geometry to conserve fuel in the heavy trucking industries.

In real-world navigation, the truck’s integrated GPS system will provide the vehicle an awareness of its own location within the 3D road geometry, which comes preloaded in the vehicle’s architecture itself. This is the reason Eaton Corporation, a major supplier of heavy-duty transmissions, is involved in the project.

“One thing Intermap is in discussion with Eaton about,” revealed Bishop, “is to possibly load the map data in the engine compartment, perhaps as an electronic control module with memory.” This bypasses the need for the driver to monitor the operations via an onboard navigation system (which, according to Bishop, isn’t that widely used by the truckers).

“In the paradigm we envision,” said Bishop, “the driver will not be in the loop. You’ll have an automatic transmission operating, maybe with an automatic cruise control system.” And that’s not too far-fetched, he said, because even today, some trucks in the market come with automatic gearshift systems.

Wei Hung, a member of Bevly’s research team leading the research effort, noted, “Early results have shown that truck fuel consumption can be reduced up to 3% without significantly increasing traveling time, when compared with a conventional cruise control system.”

“Truckers count every penny. Three percent really makes a difference,” Bishop pointed out. He predicted the same research can also benefit the consumer vehicle market, but “the concern is nowhere near the trucking industries.”

In an online article titled “Fuel Talking Points,” the American Trucking Associations wrote, “In 2006, we spent $103.3 billion on fuel.” Based on this estimate, the 3% savings promised by the Auburn University research team amounts to roughly $3 billion, not exactly chump change.

Sensitive Drivers Wanted
How does the road geometry’s accuracy affect the fuel economy? That’s the other question the Auburn University researchers are trying to answer.

“There’re some 2D road geometry data available in the geospatial industry,” observed Xiaopeng Li, Intermap’s project manager. “But Intermap’s 3D data has a high accuracy, resolution, and consistency based the company’s nationwide NEXTMap program using its proprietary airborne Interferometric Synthetic Radar (IFSAR) technology. We want to quantify the correlation that exists between the accuracy of the data and the fuel savings discovered.”

Apparently the Californian terrain offers some of the best road characteristics for this study. According to Li, several stretches of Contra Costa county and the mountainous areas toward Reno are among the 3D maps employed by the researchers for their tests.

Thinking Outside the Map
Li urges GIS developers to consider the potentials of geospatial data beyond the mapping arena. “The list of GIS applications is growing daily,” he pointed out. “This project illustrates there are many nontraditional use of the geospatial data we should look at.”