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CIV 331 – Transportation Issues and Challenges

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  1. CIV 331 – Transportation Issues and Challenges

  2. Lecture Outline • ISSUE 1: Urban Congestion • ISSUE 2: Technology • ISSUE 3: Road Design and Traffic Safety • ISSUE 4: Equality of Access • ISSUE 5: Funding and Institutions • ISSUE 6: Sustainability


  4. Urban Congestion • Most often considered to be a problem on • The urban freeway system • Intersections on arterial roadways • What are other situations where traffic congestion might be a problem? (including other modes of transportation)

  5. Why? • Why does traffic congestion occur? • Basic relationship between the demand for travel and the capacity of the facility • Capacity: • the maximum number of vehicles, passengers or the like, per unit time which can be accommodated under given conditions with a reasonable expectation of occurrence

  6. Fundamental Diagram qmax =Capacity (maximum flow) vf = free flow speed kj = jam density

  7. Solutions to congestion • Increase capacity by expanding facilities • Road building • Transit infrastructure • Reduce or manage demand • Land-use planning • Travel demand management • Increase capacity by using technology • Intelligent Transportation Systems

  8. Historically • Especially in the 1950s, the usual response to congestion was to increase capacity by building roads and mass transit systems

  9. 403,405,406 427,404,410 400,401,402 407,416 QEW Source

  10. Opposition to Highway Building • E.g. Spadina Expressway, Scarborough Expressway • Social impacts • Environmental Impacts • High Costs • Since the 1960s there have been repeated calls to shift urban passenger transportation away from private automobiles. • To date, the political advocacy has had little impact on the growth of highway traffic. • We can expect further increases in traffic and congestion

  11. Reduce Auto Demand through Transit Supportive Land Use Planning • Create Self-contained urban areas which are linked together by a transit system Source: Transit Supportive Land Use Planning Guidelines (MTO, MMO 1992)

  12. Transit supportive Land Use Planning (Cont’d) • Develop ultimate and interim boundaries for urban areas

  13. Transit supportive Land Use Planning (Cont’d) • Encourage a better mix of uses in urban areas; discourage large areas zoned for single uses Mixed use along a transit route encourages transit use Large single use areas are not transit supportive

  14. Transit supportive Land Use Planning (Cont’d) • Transit-oriented development at the neighbourhood scale

  15. Reduce demand through Travel Demand Management (TDM) • Flexible work hours • Ridesharing / HOV lanes • Promotion of cycling, walking and transit • Road pricing • Economic incentives / tax incentives (e.g. Metropass) • Parking provision and pricing


  17. Improving Facility Capacity using Intelligent Transportation Systems (ITS) • Using sophisticated methods of traffic control is another way to increase the capacity of a system without expanding facilities • Travel and Transportation Management • Travel Demand Management • Public Transit Operations • Electronic Payment Services • Commercial Vehicle Operations • Emergency management • Advanced Vehicle Control and Safety Systems

  18. Travel and Transportation Management • The Ontario Ministry of Transportation COMPASS freeway traffic management system

  19. Travel Demand Management • E.g. Ramp metering

  20. Public Transit Operations Example: Transit Signal Priority

  21. Electronic Payment Services • Highway 407 is the only fully automated toll highway in North America

  22. Commercial Vehicle Operations Electronic seals are used to ensure shipment integrity and to track containers GPS Tracking Identification of shipments • Automated Vehicle Identification • Roadside Detector

  23. Automated Highway Systems (Path Pilot project – UC Berkeley) • Eight vehicles of the PATH platoon traveled at a fixed separation distance of 6.5 meters (21 feet) at all speeds up to full highway speed. • At this spacing, eight-vehicle platoons separated by a safe interplatoon gap of 60 m (about 200 feet) and traveling at 65 mph would represent a “pipeline” capacity of about 5700 vehicles per hour. • Throughput under normal manual driving conditions at this speed would be approximately 2000 vehicles per lane per hour.


  25. Road Design and Traffic Safety • In general there has been an improvement in traffic safety over time • Improved highway design • Improved road maintenance • Improved vehicle design • Driver education • Law enforcement Source: Transport Canada 2005

  26. Highway Design and Safety Source: Transport Canada 2005

  27. Divided Highways • Highways where opposing traffic lanes are separated by grass or a raised median strip, or a barrier. • Divided highways are significantly safer than undivided highways. The benefits of divided highways are emphasized in rural areas. • Collision rate reductions of up to 60 percent can be expected when converting undivided roads into divided roads.

  28. Intersection Channelization • Channelization is defined as “...the separation or regulation of conflicting traffic movements into definite paths of travel by traffic islands or pavement marking to facilitate the safe and orderly movements of both vehicles and pedestrians” • Providing channelization for left-turn and right-turn movements can significantly improve intersection safety at both signalized and unsignalized locations. • Collision rates may be reduced by up to 75 percent with the introduction of channelization

  29. Protected Left Turn Phases • the left turn driver is directed to turn left in a protected manner through the display of a green arrow, and then directed by the display of a circular red to wait until the next cycle and its corresponding green arrow • Protected-only left-turn phasing can reduce the collision risk by at least 25 percent.

  30. Rail Crossing Warning Devices • Warning devices include flashing lights and gates • More recently in the 1990s, smart systems that control signal timings and queue lengths at rail crossings have been introduced

  31. Breakaway Devices, Energy absorbing barrier end treatments

  32. Access Management • The need for access management gained prominence in the late 1970s, as increasing suburbanization in North America collided with the commercialization of major arterials used heavily by commuters • Using 10 access points per mile as the base, it was found that each additional access point per mile increases the collision rate by about 4 percent. (Gluck and Levinson, 2000)

  33. Keep it simple!

  34. Rigid Barriers • All safety barriers must be capable of redirecting and/or containing an errant vehicle without imposing excessive deceleration forces on the vehicle occupants • Rigid barriers tend to reduce the frequency of high-severity collisions, while possibly increasing the frequency of lower-severity crashes.

  35. Limiting Intersection Angles (70° or better) • Although data is limited, intersections at angles closer to 90 degrees are generally significantly safer than acute intersections. • The angle complicates the vision triangle for the stopped vehicle; increases the time to cross the through road; and results in a larger, more potentially confusing intersection

  36. Horizontal Curve Flattening • Horizontal curves require more driver attentiveness than tangent road sections. • Horizontal curves with sharp (small) radii tend to be associated with a higher crash risk. • Safety can usually be improved by flattening curves to increase the radius.

  37. Clear Zone Widening • The clear zone is the total unobstructed traversable space within the recovery area, available to the errant vehicle • Collision reductions of up to 44 percent can be achieved with the provision of wide clear zones

  38. The opposite approach: Traffic Calming

  39. Traffic Calming

  40. Traffic Calming

  41. In the Highway Design component of this course • Geometric Cross section design • Geometric Vertical Alignment • Geometric Horizontal Alignment • Intersection and interchange layout • All of these elements of design have critical safety impacts Safety analysis will also be covered


  43. Equality of Access • Groups seen as underserved by the transport system: • Low income – • less likely to own an automobile. • When mass transit tries to compete for the market, they tend to focus on choice riders (those that have autos) and take captive riders for granted • elderly, handicapped – • Often unable to operate automobiles. • Often face accessibility barriers

  44. Accessibility and Ontario Law • Many of the most vulnerable citizens of Ontario cannot assume access to public transportation, even though the Ontario Human Rights Code guarantees the right to equal treatment in services, including public transportation services, without discrimination because of age, handicap, or family status. • The recent passage of the Ontarians with Disabilities Act ("ODA") has had a major impact on transit services, given that it explicitly requires providers of public transit to develop and make public plans for accessibility

  45. Conventional Transit Systems Ontario Human Rights Commission (2002) • About 15 percent of Ontario’s total bus fleet (about 700 buses) is now either lift-equipped, or low-floor • The TTC indicated that by 2004, 30 of its 69 subway and RT stations (including the new stations on the Sheppard line) would be fully accessible • The TTC hoped to have elevators and other accessibility features in all stations by 2012. • As well, the TTC planned to have 50 fully accessible bus routes by 2004, and a 100% accessible fleet by 2010. • TTC has since been acquiring low-floor streetcars (