2009 PE Review Course Traffic! STUDIES. Shawn Leight, P.E., PTOE, PTP Crawford Bunte Brammeier Washington University

Transcription

1 2009 PE Review Course Traffic! STUDIES Shawn Leight, P.E., PTOE, PTP Crawford Bunte Brammeier Washington University

2 Topic Areas Functional Classification Safety Financing Parking

3 Functional Classification

4 Roadway Classification Provides hierarchy of purpose/use Allows focus of funds/policies on more important facilities Assures balance between all levels of roadways

5 Functional Classification of Roads Arterial traffic movement with limited local property access Collector between road serving both traffic movement and local property access, bridges between local and arterial roads Local provides local property access with limited traffic movement

6 Access vs. Traffic

7 Rural Functional Classification

8 Roads and Traffic System Traffic Volume (%) Road Mileage (%) Principal Arterial 50 5 Minor Arterial Collector Street 5 10 Local Street 20 75

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10 Urban/Suburban Functional Classification

11 Safety Studies

12 What is the problem?

13 Safety 140, , ,000 Annualized US War Fatilities Annual US Roadway Fatilities 80,000 60,000 40,000 20,000 0 Revolutionary War War of 1812 Mexican War Civil War Spanish-American War World War I World War II Korean Conflict Vietnam Conflict Grenada Invasion Panama Invasion Persian Gulf War Somalia Operation Haiti Invasion War on Terror Annual traffic accident cost are about $2000 per typical American family

14 Primary Contributing Causes in the St. Louis, Missouri Region

15 2005 Fatality Rates by Age and Sex

16 2005 Injury Rates by Age and Sex

17 Are we making Improvements?

18 Why can t we solve the problem?

19 IDENTIFICATION OF HIGH- HAZARD LOCATIONS Crash Frequency Crash Rate Number-Rate Equivalent Property Damage Only Rate Rate Quality Control Other Indicators

20 CRASH FREQUENCY Bias Towards Higher Volume Traffic Sections Can Categorize Roadway Segments According to Functional Classification

21 CRASH RATE SEGMENT CRASH RATE A 10 8 R = SEC 365 T V L SPOT CRASH RATE A 10 6 R = SPOT 365 T V

22 Crash Rates Rate per Million Entering Vehicles (RMEV) (within 100 of an intersection) RMEV = crashes approach ADT / year * days / year 6 * 10 Rate per Hundred Million Vehicle Miles (RHMVM) (section of roadway) RHMVM = ADT * crashes / year days / year * miles in section 8 * 10

23 Crash Diagram

24 Understanding Crash Patterns at Intersections Right Angle Not Enough Corner Sight Distance Not Enough Gaps in Traffic Flow Inadequate Traffic Control Devices Traffic Signal Phase Change Interval too Short

25 Understanding Crash Patterns at Intersections Rear-end Left Turning Vehicle Stops in Through Lane Poor Sight Distance Slippery Pavement Slow Moving Vehicle on Road Vehicle Entering or Leaving Driveway

26 Understanding Crash Patterns at Intersections Side-swipe Inadequate Lane Markings Inadequate Guide Signs Poor Roundabout Design Left Turning Vehicle Stopped in Through Lane

27 Example Question Which of the following is the MOST common type of collision that is correctible through the replacement of a two-way stop with a fourway stop? a. Pedestrian b. Head-on c. Rear-end d. Right-angle

28 Financing

29 Gas Tax Given: Population of 17 million people Average vehicle ownership is 1.5 cars per person Each car is driven 10,000 miles per year Each car achieves 20 miles per gallon Additional revenue required for highway maintenance, $75 million Find: Tax increase in cents/gallon to raise $75 million/year

30 Time Value of Money P = F (1 + i) n P = A n (1 + i) 1 n i(1 + i) P = present worth of future cost or benefit F = A single future cost or benefit A = Annual amount of a series of future costs or benefits n = Number of years into the future i = Annual interest rate

31 Sample Problem

32 Parking Studies Merchants or residents complain that parking demand exceeds parking supply Undertake space inventory Assign numbers or addresses Include illegal spaces Design usage study Determine circulation interval Disaggregate by block face

33 Sample License Plate Survey Form

34 Parking Duration Number of Observations x Interval Number of Vehicles 8 15 Duration = = min./ veh.

35 Parking Turnover Number of Parked Veh. Number of Parking Spaces Turnover 12 = = 30. veh / space