Roads: Intersections Conflict Points Vehicle paths diverge, merge, or cross Typical intersection has 32
Includes buses, trolleys, ferries, and rail Only 5% of Americans use mass transit Decrease in ridership decreases revenue Decrease in revenue creates problems in sustaining the systems
Mass Transit: Rail 3 types of transit rail Light Rail Low speed street cars and trams (Houston Metro) Heavy Rail Higher speed, higher volume (NY Subway) Commuter Rail High speed, high volume rail between adjacent cities.
Rail: Shanghai Maglev Train
Background China experienced rapid economic growth in the 21 st century Greater demand for high speed passenger transportation resulted. Discussion of the feasibility of a Shanghai high speed rail began Advantages like no contact, high speed, low energy consumption, and less environmental impact led to the approval of the project. Train carries 574 and travels up to 505 km/hr
Rail: Shanghai Maglev Train Maglev: Electromagnetic levitation Electromagnetic field generated through the excitation of on board magnets and guideway magnets. Magnets then attract each other, pulling the train upward. Levitation gap stability controlled by current.
Rail: Shanghai Maglev Train Suspension: Approx. 15mm (.59in) Magnetic attraction varies inversely with the cube of the distance between the magnets. Slight variations in distance will cause dramatic force changes. How do we fix it? Closely monitoring and constantly adjusting the current
Waterways include rivers, channels, ports, locks, etc… 12% of domestic and 80% of international goods are transported using waterways Rivers like the Mississippi, Ohio, and Missouri are called “Working Rivers” 30,000 miles of navigable waterways Controlling flows and dredging bottom sediment keep channels open at necessary water depth.
Waterways: Ports Allows for Intermodal transfer of goods Standardized containers used e.g. barge to rail or truck Approx 150 ports in the U.S. 3 of which rank in the top 20 worldwide busiest ports China has more of the largest and busiest ports than any other country.
Waterways: Locks Permit ship travel around a dam or through a shallow stretch Gates open or close to control flow and consequently raise or lower a ship Approx 250 locks in the US. (29 in the Mississippi alone)
Very costly, but very effective. Used primarily for rail and roadway transportation Other uses Water supply conveyance Hydroelectric power Utilities Water storage
Tunnels: The Channel Tunnel AKA “Chunnel” Runs between Britain and France Declared one of the 7 Wonders of the Modern World by ASCE 30 miles long, 250 feet below sea level
Tunnels: Twin Tunnels Located in Shanghai, China, under the Yangtze River. Holds 3 lanes of traffic and one lane of rail Used the world’s largest tunnel boring machine (50ft diameter)
ASCE Grades ASCE- American Society of Civil Engineers The ASCE gives a report card for the infrastructure of the US Most recent grades range from D- to C+ Roads: D- Mass Transit: D Waterways: D- Rail: C- Why are these grades so low?