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EcoPRT by NCSU Research Team

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Tired of traffic? Tired of pollution? Do you want more value for the for the money spent on public transportation? EcoPRT is the answer.



EcoPRT Concept

In 2013, U.S. greenhouse gas emissions totaled 6,673 million metric tons of carbon dioxide equivalents. Out of the 6,673 million metric tons, 27% is derived from the sector of transportation.  Total U.S> Greenhouse Gas Emissions by Economic Sector in 2013

There is no reason as to why this number cannot be drastically reduced or completely eliminated.  Well known already is that the buildup of greenhouse gasses correlates to the earth's temperature rise, resulting in the phenomenon known as global warming. With global warming being a serious factor towards the future of society, it is necessary to design sustainable systems that allow for a better future. Companies like Tesla, Chevy, and Smart are proving that electric vehicles are fully capable of replacing gas operated engines. A group at NC State, known as EcoPRT, believes they have just the idea to help build a more sustainable future.

EcoPRT Team and Vehicle

            EcoPRT is a research group at NC State that is in the midst of developing a financially feasible public transit system, which has the potential to remove significant numbers of automobiles from the road replacing them with an efficient, low-cost electric transit system.  This public transit system would be comprised of completely autonomous, electric vehicles, a guideway, depot stations, and boarding stations. Each vehicle would be able to carry two passengers and their luggage. The current prototype vehicle is being designed to reach a max speed of 30 mph, but the goal of future vehicles is to reach as high as 60 mph. The hopes of designing such a system is to connect NCSU's Centennial campus with Main campus to make the commute between the two campuses easier on students, faculty, and visitors. From there, the hope is to extend the project to the rest of Raleigh and then beyond the scope of Raleigh.

EcoPRT over Traffic Light

PRT systems are designed for areas of high population density with shorter distances of travel. Areas that'd be ideal for such systems are universities, airports, amusement parks, business parks, and any small municipalities.


EcoPRT Prototype Vehicle

What actions do you propose?

ecoPRT youtube video

A video introduction of ecoPRT can be found here.

Automobile travel is the dominant mode of transportation in the US, for its convenience and flexibility. However, automobile ownership is estimated to cost $9,000 per year and have additional impacts on land use. As a little known fact, there is more square footage allocated for parking lots than for building space for typical suburban developments. Not only does this increase costs, but it creates larger distances between places further exacerbating the distance one needs to travel between destinations.

Not only can ecoPRT significantly reduce the C02 emissions on a per mile basis, but it can also be the catalyst for creating more walkable communities which further reduces the need to travel farther distances.

For a typical automobile being driven 12,000 miles, 6.6 tons of C02 is created. If we look at an equivalent number of miles driven on in an ecoPRT vehicle, 12,000 miles equates to just 0.9 tons of C02 creation annually. However, since ecoPRT reduces the need to have parking lots and large roads, there is an additional factor to reducing C02 emissions. The creation of mixed-use walkable communities can reduce the vehicle miles traveled (VMT) significantly, and estimates vary widely. An example of VMT per capita and city density can be seen in this graph:

VMT vs Population density

Without going into too much detail, what prevents denser mixed use developments from occurring is the concern over traffic and parking as outlined in the seminal book, “The high cost of free parking” by Donald Shoup. EcoPRt could provide an alternative to the status quo of driving and parking that could significantly affect the VMT per person. Small changes in density can have striking affects on vehicle travel as shown in the plot. We estimate ecoPRT could reduce total travel miles by as much as 50%. So instead of 12,000 miles of travel, we might see 6,000 miles of travel, equating to just 0.45 tons of C02 annual emissions.

In order to estimate the CO2 reductions from ecoPRT, we took Raleigh, North Carolina as an example.  We have looked at a 20 mile system which captures much of Raleigh's downtown area:

Raleigh Simulation

This simulation takes into account the demographic data from the Wake county real estate database looking at housing, office, and retail spaces.  Essentially, housing, commercial and retail spaces were used to calculate demand at each location.  The station locations capture approximately 32022 people in housing, 45616 people in commercial, 90117 daily trips for retail.    The simulation was modeled for an evening commute.  At 1.5s headways: 2600 vehicles are used with double track length of 21.6 miles and total capacity is 12,500 trips/hour.  Overall, capital costs would run about $100 million for installation.  It would not be out of the question for 50% of trips within the transit area to be taken by PRT.  On average in the US, the number of trips per day a household generates is 10.  It is not unreasonable to assume, even without any additional development, there is an immediate demand of 50,000 trips per day.  Overtime, with the convenience of ecoPRT and as development patterns converge on mixed-use walkable communities and as Raleigh becomes less-car dependent, the same system may see demands upwards of 100,000 trips per day.

If Raleigh is a good example, out of 440,000 people, with just a 20 mile track, over 50,000 trips per day could be taken with ecoPRT as opposed to the automobile.  Initially, this equates to a reduction of 55 million car miles with a CO2 savings of 26,000 tons of CO2 per year.   As Raleigh evolves more into a compact walkable community, automobile trips will continue to diminish which would be replaced by people walking and taking ecoPRT.  Five to 10 years in the future, an equivalent of 50,000 tons of CO2 per year could be reduced in this one small 20 miles segment alone. 

Funding is difficult for novel transit methods

Given ecoPRT's potential and Personal Rapid Transit (PRT) in general, the obvious question presents itself: Why does Morgantown have the only operational PRT system in the United States? We had the opportunity to attend the Public Sector Innovation Workshop sponsored by San Jose where they discussed Automated Transit Networks and this very challenge (San Jose 2013). Additionally, funding was readily discussed in the Podcar City conference in Washington DC (Podcar city 2013). In our research and interviews, we found that it is due to a number of factors:

  • Transportation grants link to existing transit modes (ex. Highway, rail, bus). PRT systems are still relatively rare, and so current funding guidelines seem to focus on incremental technological improvements over existing systems.

  • Increased costs from contractors for unknowns/risk. Likewise, PRT systems are relatively new, and a body of expertise is not well known. Contractors increase costs to account for the unknown.

  • Lack of education of PRT to public and key decision makers. PRT operates very differently from existing bus and train systems, so it is often difficult to communicate the benefits to the public and key decision makers.

  • Attitude that PRT needs to be self funded. Also related to the lack of funds for PRT, there is a sense that PRT should compete with existing transit modes despite the disparity in available funding.

  • Fear that PRT cannot handle capacity. Many point to the capacity of light rail as being the single most important factor in choosing a transit technology instead of choosing a technology that has the right fit for the projected capacity needs of the system. Additionally, line capacity does not necessarily relate to system capacity depending on the network.

  • Opposition to elevated guideways. Elevated guideways may recall images of large overhead highways and railroads, not the smaller footprint of PRT systems.

  • A lack of standards. Transportation agencies and cities worry that they will be locked into a proprietary technology. Should systems evolve, earlier adopters could be left maintaining legacy technology. Another concern is the lack of competition of PRT vendors and the reliance on sole source vendors.

  • Regulations (ex. Brick Wall Stop) originally designed for railways are being applied to PRT systems, though it may not be an optimal match.

ecoPRT in RTP

EcoPRT is Driven through Market Forces

The key differentiating feature of this personal rapid transit system is the economic model. With a guideway cost of $1 million per mile, our system offers the least expensive capital and operating costs compared to other transportation options. As such, a very different business model can be applied. Passengers using this system will be billed by the mile traveled, in much the same way that cell phones bill by the minute. The cost per mile will comprise the aggregate of:

The other side of the equation deals with market adoption. Our aim is to create a system that is no more expensive than typical vehicle operation. The IRS pegs business travel with a car at $0.55/mile. ecoPRT's cost on a per mile basis breakdown as follows:

  • vehicle                           $0.10
  • electricity                       $0.01
  • guideway infrastructure $0.05
  • station costs                  $0.02
  • operations                      $0.04
  • car maintenance            $0.10
  • guideway maintenance  $0.02
  • station maintenance       $0.05
  • insurance                        $0.11


Loading comparison

Figure 1.  Comparing the loading of ecoPRT on a guideway to that of a train.

Here, we can see that ecoPRT is competitive with automobile ownership. To estimate growth however, it is worth looking at the other stakeholders who benefit from ecoPRT. Those are as follows:

  1. Riders benefit financially since the cost is competitive with automobile

  2. Riders benefit from time productivity. The American commuter spend 38 hours in traffic every year.

  3. Developers: If builders didn't have to build additional parking, the cost of the building could be less which would have pass-down savings to the building users.

  4. Departments of Transportation: Savings on upkeeping infrastructure.  It is much less expensive to build overpasses and bridges for small light-weight vehicles, compared to typical roadways. For example, ecoPRT with 2 passengers will weigh no more than 1000 lbs. A semi-truck can have a load as great as 105,000 lbs., a 100x factor.

  5. Environmental costs, local regional and national governments are motivated to reducing air pollution that can cause long term health risks for the population and global warming.

Keeping the cost of the system extremely low with markedly improved point-to-point travel times will provide significant incentives for ridership.

Compare this model to a light rail system where the track cost is typically $50 million per mile or more. Vehicle cost is also substantial. There is little hope of amortizing these costs completely to passengers, hence the need for substantial government subsidies. Train travel times may be greater than car travel times because of frequent stops and wait times for the train.

The proposed starting point for this system is at North Carolina State University (NCSU).  As an example, consider the hypothetical phased approach for our transit system as seen in Figure 2. For Phase One the estimated infrastructure cost for a bidirectional rail with 8 stops along 1.7 miles would be $5 million. Following on Phase One's success, Phase Two could include another 21 stops with an additional 4.8 miles of single direction guideway at a cost of $9.5 million. Overall, the carrying capacity in any one direction would be ~5,000 passengers per hour, well above the current ridership levels. In terms of transit time, the worst case scenario would be just minutes traveling from Hillsborough St. to the MRC building on Centennial campus (1.7 miles). If we amortize the cost over 30 years for Phase I and II, and assuming 10,000 passengers trips per day, infrastructure accounts for only 13 cents per passenger trip.

phase I and II NC State ecoPRT plan

Figure 2. An example of Phase 1 and Phase 2 deployment of the automated transit network at NCSU. Phase 1 (in purple) shows bi-directional guideways reaching up from Centennial campus to Hillsborough St. Phase 2 includes additional stations to increase coverage.

The advantages of this approach include:

  1. An existing budget of approximately $5.5 million per year for buses, maintenance, fuel and drivers

  2. Existing ridership of approximately 15,000 rides per day

  3. Significantly reduced resistance to deployment on campus, including easier right of way acquisition and low impact on the surroundings.

  4. Significantly improved rider experience for students, including much lower wait times and travel times (4 minutes versus 20 minutes for a 2-mile trip)

  5. Significantly reduced environmental impact due to elimination of the carbon footprint and exhaust fumes of diesel buses.

Because of the per-mile pricing model and the low cost per mile traveled from the passenger perspective, the opportunity for organic, free market expansion of the system is significant. Imagine an NCSU personal automated transportation system reaching out to local shopping centers and the stadium a mile away. It is easy to imagine that businesses will want to connect to a system that brings in new customers without having the additional burden of building more parking spaces. Because of its existing base traffic and the large mass of students at NCSU, the NCSU core system provides value that others will want to access. This process is self-feeding and creates an important positive feedback loop as the system grows.


Profile picture of ecoPRT compared to other modes of transit

Figure 3. Form factors of transportation vehicles compared with ecoPRT.

Who will take these actions?


A PRT system will require a collaborative effort from the EcoPRT team, government agencies, as well as private industries. First and foremost, the EcoPRT team will be tasked with completely developing the technology necessary for an autonomous vehicle to drive upon an elevated guideway. Once that this has been completed, the team will work with primarily government transportation agencies to gain approval to build guideways in pre-existing civil structures. Finally, private industries will be brought onboard to expand the guideway system to commercial business hubs. By gaining commercial partnerships, the cost of building and maintaining guideways will be spread across several businesses and in return, provides a sustainable urban transportation system that delivers patrons to their place of business. In preparation for this stage of the project, the EcoPRT has already contacted various shopping centers and government officials in the Raleigh area to promote the PRT concept. Currently, the team has received numerous letters of support for this team’s goal of developing an environmentally friendly transportation for the Raleigh area. 

Where will these actions be taken?

In order to make this system successful,  the team believes that the system needs to start out in a small, densely populated area to reach its maximum efficiency, with the maximum efficiency being comprised of financial costs, amount being transported, and rider satisfaction. The team believes that PRT systems would be most beneficial in university settings, airports, amusement parks, business parks, and within certain municipalities. PRT systems can be built in any region and can be designed to be built to fit any given set of requirements. There is no restrictions to as which such a system can be built, but in order for it to be built worldwide it must first start out somewhere. With it being a NCSU project, the team wishes for it to have its start here at NCSU.

                As stated previously in the summary, the project has its roots here at NC State university, so the team would like to implement its first functioning system here on NCSU's campus. After time, the team would like to learn how the local campus community responds to the system and then make any necessary changes to any negative feedback received by the community. With all information obtained, the team would like to then build off of the current system to local areas of business and university apartment complexes. After a secondary extension of the system, the team wishes to extend its reach even further throughout Raleigh. As this process occurs in Raleigh, there is no reason as to why it can't occur simultaneously  elsewhere, but with such great amounts of capitol being used financial limitations will occur. After others see the success of the system the team hopes that investors or government backing of some sort will back the project and allow growth to occur.

How much will emissions be reduced or sequestered vs. business as usual levels?

The largest 300 cities in the US hold 90 million people.  Taking Raleigh as an example, we could plant an appropriately sized ecoPRT system in each city.  The immediate CO2 reduction for all the cities could be 5.3 Million tons of CO2 per year.  Overtime, it could double to 10 Million tons of CO2 per year.

As we mentioned, the 20 mile ecoPRT system initially costs $100 million and generates a CO2 reduction of 50,000 tons per year.  If we assume a 30 year infrastructure life, then we can calculate the cost to reduce one ton of CO2.  ($100M/(50,000 tons per year X 30 years).  The result is that for every $67 in infrastructure spent, one less ton of CO2 will be emitted into our atmosphere.

What are other key benefits?

ecoPRT at NCSU

EcoPRT proposes an innovative, new transportation modality that brings five key benefits to the marketplace:

1.         Because of its infrastructure and vehicle size, EcoPRT can occupy existing rights of way and fit almost anywhere, even in the densest urban areas.

2.         EcoPRT is specifically designed to be an extremely low cost option – so low that an EcoPRT system can recoup the cost of installation and operation from fares and can also be considered for installation with private investment capital.

3.         Because of the low costs involved, it is possible to move EcoPRT infrastructure as conditions and requirements change.

4.         Because stations are lightweight, inexpensive and do not increase travel times for riders, stations can be built at frequent intervals and at every major point of interest.

5.         Private entities can fund stations and guideway and recoup their investments over time through the fare structure. 

What are the proposal’s costs?

The key differentiating feature of the EcoPRT transit system is the economic model. With a guideway cost of $1 million per mile, EcoPRT offers inexpensive capital and operating costs.  At a per mile cost of 51 cents, ecoPRT can be market driven and allow an accelerated deployment compared to existing transit solutions that are too expensive and rely on government subsidies to be built and operated.

Our milestones are as follows:

  1. Currently, we have developed a prototype that can be remotely operated.  We are working on autonomous driving, collision detection, and the construction of a test track.
  2. With additional funding of $100,000 to $500,000, we will demonstrate a working system level solution that passengers can ride over 0.25 miles.
  3. With funding from $5M to $10M, we can develop a system on NC State Campus that acts as the major connector between Centennial Campus and Main Campus.
  4. Additional funding of $20M could lay down an additional 20 miles of guideway through Raleigh allowing for 100,000 trips per day.


In deploying ecoPRT, a very different business model can be applied. Passengers using this system will be billed by the mile traveled, in much the same way that cell phone companies bill by the minute.

By keeping the cost of the guideway extremely low, the target fare is 55 cents per passenger-mile for this system. This price will match the cost of operating a typical motor vehicle (55.5 cents per mile IRS reimbursement rate) and bus operation at NC State (Wolfline's $2.20 per trip). Low cost, convenient access and minimal wait times combined with markedly improved point-to-point travel times will provide significant incentives for ridership. In addition, by creating corporate partnerships with shopping centers and other public hubs, the cost of implementing and maintaining a PRT system in an urban area can be deferred to private businesses by building guideways to their place of business. 

EcoPRT prototype vehicle

Time line


This project has been underway since the beginning of last year and since then the team has developed a vehicle and is currently in the midst of constructing a test track. With that being said, the research phase is not complete, but the hope is that within another year's time all the research will be complete, along with public backing and regulations being met, thus allowing the construction process to begin.

By 2017 the hope is that the system will be completely operational here at NCSU. After the Phase I of the system is up, and if proven successful, an expanded system on the univesity campus, Phase 2, would occur by 2019. Also by then, Raleigh could have additional lines installed which feed into NCSU's system.

Also by 2019, and given ecoPRT's market driven approach, additional systems could be planned for other cities, universities, shopping centers, and business campuses.  A veritable paradigm shift in transportation could take place which would quickly change how we think of transportation today.  EcoPRT could change the dominance of automobile ownership allowing people a less expensive, lesst traffic ridden, more economical, and practical means for getting around in downtown and urban areas.  With CO2 reductions being enormous, ecoPRT can play its role in a sustainable transportation future for the world.

Related proposals

Mass transit utilizing autonomous electric vehicles on a solar powered tollroad

Sustainable Low-Carbon Transport System


  1. Alex Ruth, EcoPRT, Personal Rapid Transit Research & Electric/Autonomous Vehicle Prototyping Proposal, Research Grant Proposal, pp. 2-4
  2. Donn Fichter, Individualized Automatic Transit and the City, Donn Fichter 1964, Providence, Rhode Island.
  3. MARK REUTTER, The Wilson Quarterly (1976-), Vol. 33, No. 4 (AUTUMN 2009), pp. 26-33
  4. Morgantown Personal Rapid Transit System Operation Description Manual M-PRT-1-1, pp. 2 & 4
  5. Morgantown Personal Rapid Transit Website
  6. EcoPRT Website
  7. EPA Website
  8. Hyperloop Website
  9. Toyota Website
  10. Ultra PRT Website
  11. Hyperloop PDF
  12. PRT Comparison Paper