Question

In: Civil Engineering

A freeway has the following characteristics: 6 lanes, 3 in each direction 13’ lanes 8’ right...

A freeway has the following characteristics:
- 6 lanes, 3 in each direction
- 13’ lanes
- 8’ right side lateral clearance
- Total of 4 ramps in the 3 miles upstream and 3 miles downstream of the midpoint of the facility
- 2% upgrade for 1.5 miles
- Urban facility with 50% delivery trucks and 50% freight trucks
- 8% trucks
- 3,400 veh/hr in the analysis direction in the peak hour
- 955 vehicles in the peak 15-minute time period

(3) What is the free flow speed of the facility?

(3) What is the passenger car equivalent flow rate?

(3) What is the estimated operating speed of the facility?

(2) What is the density of the facility?

(2) What is the LOS of the facility?

(2) Describe what the LOS indicates about how well the facility is operating?

Solutions

Expert Solution

Assume, Base free flow speed (BFFS) = 75 mph

Lane width = 13 ft

Reduction in speed corresponding to lane width, fLW = 0 mph

Lateral Clearance = 8 ft

Reduction in speed corresponding to lateral clearance, fLC = 0 mph

Interchanges/Ramps = 4 /6 mile = 0.67 /mile

Reduction in speed corresponding to Interchanges/ramps, fID = 0 mph

No. of lanes = 3

Reduction in speed corresponding to number of lanes, fN = 3 mph

Free Flow Speed (FFS) = BFFS – fLW – fLC – fN – fID = 75 – 0 – 0 – 3 – 0 = 72 mph

Peak hourly volume, V = 3400 veh/hr

Peak 15-min flow = 955

Peak-hour factor = 3400/(4*955) = 0.89

Trucks = 8 %

2% upgrade for 1.5 miles

50 % delivery trucks and 50 % freight trucks

fHV = 1/ (1 + 0.04 (2.5-1) + 0.04 (3.0-1)) = 1/1.14 = 0.877

fP = 1.0

Passenger Car Equivalent Flow Rate, Vp = V / (fHV * PHF*n*fP) = 3400/ (0.877*0.89*3*1.0) = 1452 veh/hr/ln

Estimated operating speed, S = FFS = 59.3 mph

Density = Vp/S = (1452) / (72) = 20.167 veh/mi/ln

LOS C

Density of LOS C should lie between 18 - 26 veh/mi/ln

Facility is operating at freedom to maneuver is noticeably restricted and queues may form behind any significant blockage on the freeway.

Ally Wells answered 6 months ago

Next > < Previous

Related Solutions

An existing urban freeway with 4 lanes in each direction has the following characteristics: Peak hour...

An existing urban freeway with 4 lanes in each direction has the following characteristics: Peak hour volume (in peak direction) 7,070 veh/hr Trucks: 10%, 2,012 vehicles observed in the peak 15-minute time period Lane width = 11’ 4’ right side lateral clearance 1.8 ramps per mile Rolling terrain Determine the LOS in the peak hour. Clearly show your results for freeflow speed, demand flow rate, capacity, mean operating speed, and density along with the LOS.

6-lane freeway (3 lanes in each direction) in level terrain has a current one-directional volume of...

6-lane freeway (3 lanes in each direction) in level terrain has a current one-directional volume of 5000 veh/h; it is estimated that in 3 years, volume will have increased to 5600 veh/h. The traffic mix includes 10% trucks. The free-flow speed has been measured at 70 mph and the PHF is 0.95. a) Determine the current LOS. b) Determine the LOS in 3 years. c) After the initial three years, traffic grows at 4% per year, when will capacity be...

A six-lane freeway with three lanes in each direction has regular weekday users. The lanes are...

A six-lane freeway with three lanes in each direction has regular weekday users. The lanes are 12 feet wide, the right-side shoulder is 2 ft wide, and there are two ramps within 3 miles upstream and two ramps within 3 miles downstream of the segment midpoint. The highway is on rolling terrain with 12% large trucks and buses and 2% recreational vehicles. The peak hour factor is 0.85. Determine the maximum hourly volumes that can be sustained at LOS C...

[HCM for Basic Freeway Segments] A four-lane freeway (two lanes in each direction) has an observed...

[HCM for Basic Freeway Segments] A four-lane freeway (two lanes in each direction) has an observed demand volume of 2400 veh/h (one direction) during the peak hour. The freeway is on rolling terrain and the traffic stream consists of passenger cars and trucks only. The peak-hour factor is 0.75 and the traffic is all commuters. If the peak 15-min demand flow rate under equivalent base conditions is estimated to be 2000 pc/h/ln, what is the percentage of trucks in this...

A six-lane freeway with three lanes in each direction is on a level terrain and has...

A six-lane freeway with three lanes in each direction is on a level terrain and has 11-ft lanes with a 4-ft right-side shoulder. The total ramp density is 2 ramps per mile. The directional peak-hour traffic volume is 5400 vehicles with a peak-hour factor of 0.95 and all familiar users. The traffic stream includes 5% trucks and another 5% buses and no recreational vehicles. The city has decided to ban all heavy vehicles from using the freeway during the peak...

A six lane urban freeway (three lanes in each direction) in mountainous terrain has 10-ft lanes...

A six lane urban freeway (three lanes in each direction) in mountainous terrain has 10-ft lanes and obstructions 5 ft from the right edge. For every mile of freeway, there is one interchange. The traffic stream consists of mostly commuters with a peak hour factor of 0.84, peak hour volume of 2500 vehicles, and 4% recreational vehicles. What is the LOS? Assume base free flow speed of 70 mph

[HCM for Basic Freeway Segments] A six-lane freeway (three lanes in each direction) operates at the...

[HCM for Basic Freeway Segments] A six-lane freeway (three lanes in each direction) operates at the maximum service flow rate (MSF) of LOS D conditions during the peak hour with an observed demand volume of 3500 veh/h (one direction). The free flow speed (FFS) of the freeway is estimated to be 65 mi/h. The freeway is on rolling terrain and the traffic stream consists of passenger cars and buses only. The PHF is 0.85 and the traffic is all commuters....

Problem 1 On freeway 3 lanes each direction serving traffic to and from coastal beach resorts,...

Problem 1 On freeway 3 lanes each direction serving traffic to and from coastal beach resorts, determine the level of service when the following parameters are given: PHF = 0.90 Lane width = 11 ft Rolling terrain Average space of interchanges = 2 miles 8% trucks and 2% RV Right shoulder lateral clearance = 5 ft BFFS = 70 Problem 2 1. Determine the level of service for a 3000 ft segment of a four –lane highway with 3% grade,...

An existing rural 4-lane freeway (2 lanes in each direction) has 11-ft lanes and 2-ft lateral...

An existing rural 4-lane freeway (2 lanes in each direction) has 11-ft lanes and 2-ft lateral clearance. The freeway hasa peak-hour volume of 1,800 veh/h in one direction, 5% trucks in the traffic stream, and a PHF of 0.92. The freeway has 1 cloverleaf interchange within three miles of the midpoint of segment, and runs through level terrain. No recent field speed data is available. a) Using HCS7, determine the LOS during the peak hour. b) What is the capacity...

Problem Statement: A four-lane (two-lanes in each direction) freeway is on rolling terrain with 11-ft lanes, a...

Problem Statement: A four-lane (two-lanes in each direction) freeway is on rolling terrain with 11-ft lanes, a 5-ft lateral clearance on right side and 3-ft lateral clearance on the left side of the traveled pavement. The measured free-flow speed is 60-mph. During the peak hour there are 12% large trucks and buses and 6% recreational vehicles. The freeway currently operates at capacity during the evening peak hour. If an additional 11-ft lane is added, and all other factors stay the same,...

Subjects