University of Detroit Mercy<br />AEV 5060: Innovation and System Architecture for Advanced Electric Vehicles<br />April 27, 2011<br />Scope:<br />The scope of this project is to develop a On-Demand Personal Rapid Transportation (PRT) System for use around large corporate, as well as mid to large college campuses. The Team will take on the role of a Transportation Consulting Firm scoping the infrastructure necessary to develop a system with a brief business case analysis. The PRT system would replace many of the current shuttle or bus transport modes with comparable or superior levels of service by improving both waiting and trip times leading to improved business productivity by giving time back to the riders.<br />Fundamental Elements of the PRT System:<br />PRT is an emerging public transportation technology designed to address the needs of the sprawling urban environment. In this study, a PRT system will be designed for the limited operating area of the Ford Motor Company Research and Development Campus in Dearborn Michigan and compared to the current courtesy shuttle bus service which serves the campus today. Since being introduced in the 1960’s PRT systems has evolved through a variety of academic, governmental and private development programs. The key characteristics of PRT system include:<br /><ul><li>On-demand, origin-to-destination service: At the originating station, a rider would board a waiting vehicle, or POD, and input their desired destination station. The POD would then transport the rider to the desired destination with no intermediate stops.
Small, fully-automated vehicles: PODs are intended to operate under computer control and require no operator or driver. PODs are designed for two to four passengers and would provide ADA accessibility.
Exclusive-use guideways: Tracks or “guideways” for PODs would be designed to avoid at-grade crossings with pedestrians or other types of surface vehicles by designing the guideways as an elevated system.
Off-line stations: Off-line stations are designed with a “siding” guideway so that PODs not stopping at a particular station can bypass that station.
A network of interconnected guideways: PRT systems are usually designed as an interconnected network of guideways connected at key junctions. These junctions allow PODs to select clear paths through the network. </li></ul>As a new technology, PRT combines the elements of current automotive, computer networking and transit technologies using state-of-the-art technologies including: advanced propulsion systems, computer controlled switching and guidance, and high speed controls and communication. <br />There are several different approaches that can be taken in the design of a PRT system or network. This study reviews the following system components and characteristics which will be used to simulate the Ford-PRT (FPRT) specific network:<br />PRT System Components<br /><ul><li>Guideway: This is a dedicated transport surface which can be at-grade, elevated or underground. The guideway is structured as a network which allows vehicles to select the most direct route between stations. PRT guideways are generally classified as one of the following:
Open guideway: Consist of a flat surface that supports the vehicle. Vehicles typically have rubber wheels and automated steering. Vehicles sense their position by detecting their position relative to guideway's curbs.
Captive bogey: Vehicles are supported by the chassis it rides on. The vehicles typically have horizontal wheels captive within the guideway - the guideway steers the vehicle.
Suspended: Vehicles are like Captive Bogey but are suspended from the guideway.
Vehicle or PODs: Vehicle design is dependent on guideway type and will vary by vendor. Vehicle size tends to be in the range of two to four passengers.
Propulsion: Primarily electric propulsion. With electric propulsion comes two considerations – power source and propulsion method. Power source can be provided by onboard batteries or a line-side power rail. The propulsion method is typically provided by traditional rotary electric motors driven wheels or linear electric motors that propel the vehicle via electromagnetic resistance.
Energy Source: Sources include conventional coal, nuclear or petroleum based plants or alternative sources such as solar, wind or fuel-cell technologies.
Switching: There are two general types of switching - mechanical and electromagnetic. Mechanical switching is typically a vehicle-mounted. In the event of mechanical switch failure, the problem is isolated to the vehicle. Electromagnetic switching systems place the switch in the guideway; however, like mechanical switches, a vehicle mounted switch is preferable to avoid a system wide shutdown in the event of a switch failure.
Stations: Off-line guideway designs are preferred so that through-traffic can bypass vehicles picking up or dropping off passengers. This provides direct, non-stop service.
Maintenance and Storage Facilities: A depot is needed to service, clean and store vehicles not being used. </li></ul>PRT System Characteristics<br /><ul><li>Headway: Refers to the spacing between vehicles and can be defined in terms of time or distance. The spacing of PODs on the guideway directly influences the overall maximum passenger capacity of the system.
Travel Speed: Typical line speed is in the range of 25 to 45 MPH.
Capacity: PRT systems vary their capacity by increasing the number of vehicles or PODs in the system and by reducing the headways between vehicles. </li></ul>The FPRT Network will use the following assumptions to support the base design as well as to support the Hermes Network Simulator. <br /><ul><li>Guideway: One-way, Elevated, Open Guideway
Vehicles or PODs: Based off the four passenger autonomous ULTra vehicle design, four rubber pneumatic tires, front-wheel steering and conventional damped spring suspension.
Propulsion: Battery powered electric vehicle, Rechargeable Lithium-Ion Battery power source, 7kW Synchronous AC Drive Motor
Energy Usage: Solar Panel system supplemented by Grid power when necessary (with station opportunity charging system)
Switching: Automated Front-wheel steering system
Maximum capacity before producing errors where PODs are forced to bypass target stations due to station congestion. </li></ul>The FPRT system will address the following customer needs versus current courtesy shuttle bus system:<br /><ul><li>Improved average travel speed and trip times: When compared to the current courtesy shuttle service, it appears that the FPRT system could achieve reduced waiting and trip times of about 23 minutes per Rider - 9 minutes reduced wait time and 14 minutes in travel time to destination. This is primarily due to the non-stop, on-demand nature of FPRT operations. Estimates are for station to station travel only and do not include the time to walk to a station which will vary from building to building.
Improved productivity: Less time spent waiting and traveling provides more time for riders to spend on daily business activities. It is estimated that the time saved versus the current courtesy shuttle service is about 23 minutes per rider. Assuming a $125k average yearly compensation and a typical eight hour working day (48 weeks per year), this would translate to over $46 Mils over a ten year period versus the current Courtesy Shuttle service ridership rate.
Energy use and environmental impact: PRT systems will operate non-stop, on-demand service using lightweight vehicles on exclusive-use guideways. It is therefore estimated that PRT systems will consume 300 percent less energy than the current courtesy shuttle service and could achieve an automotive equivalent fuel consumption of 70-90 miles per gallon.
Reduced pollution: Because of the use of rubber tires and electric propulsion, PRT systems will deliver lower noise and air pollution than the courtesy shuttle service.
Increased safety and security: Advanced monitoring (intercom and CCTV) and control systems will provide constant rider safety at all times. Furthermore, PODs will be equipped with emergency front and back exits that will permit occupants to exit a stopped POD and access the guideway. Guideways will be equipped with side mounted security handrails and surface treatments to permit stranded riders to walk safely along the guideway to the nearest station or to several installed emergency/service steps which lead down to ground level. </li></ul>Challenges for the FPRT Network include:<br /><ul><li>Engineering and planning expertise: There is limited experience or understanding in the transit industry regarding PRT design and operations.
Open technology development: PRT technology is currently under development by several independent suppliers.
Development and application of standards: Few standards exist for PRT systems. However several are applicable such as the American Society of Civil Engineers which developed standards for Automated People Mover industry and the National Fire Protection Association (NFPA), which developed NFPA Standard 130 covering fire protection and fire life safety issues applicable to fixed guideway transit and passenger rail system.
Capital costs: Engineering cost estimates from comparable conventional elevated guideway systems built in the United States were used as part of this study to derive engineering capital cost estimates. These estimates indicate that capital construction costs for a one-way elevated PRT system average $15 million per mile.
Operating and maintenance (O&M) costs: PRT systems are highly automated and therefore require low staffing levels, energy use and maintenance. Using data provided by PRT developers indicate that O&M costs per passenger mile might range from $0.30 to $0.80. </li></ul>FPRT Simulation Model<br />A dedicated simulation PRT modeler; the Hermes Network Simulator (Xithalis, 2008) will be used to. It is a free online program which allows the implementation of a predictive demand traffic management algorithm to help simulate different rider demand and guideway layout strategies. <br />The program is written in Java and permits the network designer to:<br /><ul><li>Design a PRT network overlaid onto a map, scaled with stations and interconnected guideways
Set a series of parameters (speed, headway, rider demand, etc.)
View statistics and analyze the network for traffic management opportunities to optimize capacity, reduce wait times and reduce cost.</li></ul>The results will be used to prove out overall network feasibility. The results will also be used to calculate overall costs based on total guideway length, the number of stations and the number of PODs to achieve efficient and cost effective operation. Based on this information the following systems costs have been calculated.<br />FPRT Layout<br />Station 1: PDC near the Design Center Dome and main Cafeteria.<br />Station 2: PDC, near the Atrium entrance<br />Station 3: AEC<br />Station 4: Scientific Research Center<br />Station 5: Dynameters Center<br />Station 6: Buildings 1 thru 5<br />Depot: Located South of the Scientific Research Center on a green-field sight<br />The Hermes Simulator results indicate that the total length of both on-line and off-line guideways is about 3.92 miles. Based on existing capital cost estimates of $15 Mils per mile, the estimated capital construction costs would be about $58.8 Mils. <br /><ul><li>With the current level of energy prices and the concern over dependence on imported foreign oil, the increased energy efficiency of PRT makes them environmental, economic attractive.