Reference no: EM13341955

Assignment 1 

Description Marks out of Weighting(%) Due date 

Assignment 1 200 marks 20% 07 October 2014 

Rationale 

This assignment is designed to test your achievement of the learning objectives of Modules 1, 2, 3, 4, 5, 6, 7, 8, 9 &10. 

Special instructions: 

Assignment 1 must be submitted by the due date via study desk link as attachment (word or scanned .pdf file). 

Information provided is generally adequate. If any assumptions are required, those should be clearly stated. The answers should be well set out and clearly shown including all required calculations, estimation of qualities of road construction materials, etc. No excel files will be accepted as a part of your calculations. 

Not a formal report is required, but clearly presents your answers (hand written or typed) in a format appropriate to a student presenting answers to examination questions. 

Penalty for late submission of assignment 1 

Please note that the onus is on students to organise their affairs so that they can achieve the educational objectives of the course and submit assignments for assessment no later than the due date. The onus is also on the student to provide, if requested, proof of date of despatch. 

Work commitments will not be considered a legitimate reason for late assignments. 

If students submit assignments after the due date without legitimate and extenuating circumstances (e.g. illness substantiated by a medical certificate) then a penalty of 5% of the assigned mark may apply for each working day late up to a maximum of ten working days at which time a mark of zero can be recorded for that assignment. 

Problem 1 – 

Four similar intersections in a small town have the following annual crash data and total approach volumes. Using Rate Quality Control method, determine the hazardous intersection(s). Use 95% confidence level. 

Intersection 1 2 3 4 

Traffic volume (vehicles per day) 4500 4200 3275 4600 

Number of crashes in 2012 16 15 17 20 

Note: Please refer to the PowerPoint presentation file uploaded to the course study desk, titled: Road safety analysis 

Problem 2 – 

Determine the minimum radius a curve for a highway with a design speed of 100km/h. The grade is level, super elevation is 6%, and the side friction is 0.12. 

The coefficient of deceleration is 0.29, and the driver reaction time is 2.5 seconds. For your design above what is the closet distance of a structure (fence) along roadside curve may be built from the centreline of the inside lane. The height of the concrete fence will be over the height of driver seat. 

Note: Use the attached formula sheet, if necessary. 

Problem 3 – 

For the following four-leg intersection and demand table as shown below, using Webster’s equations, determine the optimum cycle time and green split time. Assume a four phase timing plan as shown with 3 seconds of amber time and all read time is 2 seconds. Total lost time per phases is 4 seconds including start and end losses and all red time. 

Lane 1 2 3 4 5 6 7 8 

Volume (vph) 500 200 275 55 325 115 350 60 

Saturation Flow rate 1650 1500 1700 450 1600 1450 1850 550 

Figure 1: Four-leg intersection 

Figure 2: Four phase plan 

Note: Please refer to the PowerPoint presentation file uploaded to the course study desk, titled: Traffic signal design 

Problem 4 – 

For the following speed-flow relationship, determine the maximum flow, free flow speed, density at maximum flow and jam density. 

q=280 u-72 u ln?(u) 

Sketch the resulting speed-flow, speed-density and density-flow graphs. 

Problem 5 –  

When the volume at a long section of a unidirectional highway was 800 veh/h and the density was about 25veh/km, a large truck joins the traffic stream and travelled at a speed of 10 km/h for a length of 2.5 km before turning off from the road to a construction site. Vehicles just behind the truck, travel at the speed of the truck which results in the formation of a platoon having a density of 100 veh/km and a flow of 500 veh/h. Estimate the number of vehicles in the platoon when the truck leaves the highway. 

Problem 6 –  

A 5.0 km long new highway has two 3.5 metre lanes (one lane in each direction of travel) and sealed shoulders of 1.0m width are provided on both sides of the road. This project is about to start sprayed seal surfacing on top of existing primer seal, and the design requirements are prepared as detailed below: 

Seals: Double/Double - Class 170 + 5.5% cutter + 0.5% Adhesion agent 

1st coat: Application rate of 20 mm aggregate = 85 m2/m3 

Bitumen application rate = 1.40 l/m2 

2nd coat: Application rate of 10 mm aggregate = 145 m2/m3 

Bitumen application rate = 0.99 l/m2 

The 2 coats of sprayed sealing should be completed within a day before allowing traffic; and the surface should be swept before the application of prime. When handling the aggregates at similar sites, it was found a loss of 5% due to stockpiling and spreading. Drag booming is recommended after 2nd coat of sealing. Density of the bitumen is 1 kg/lit. 

The cost of bituminous materials on site is as follows: 

Material Cost 

Class 170 bitumen, $/tonne 650.00 

Bitumen cutter, $/litre 1.10 

Adhesion agent, $/kg 12.00 

20 mm Aggregate (precoated), $/m3 34.00 

10 mm Aggregate (precoated), $/m3 38.00 

Costs which may be associated with carrying out the work are estimated to be: 

Activity Cost 

Sweeping pavement, $ per square metre 0.07 

Drag brooming pavement, $ per square metre 0.05 

Incorporate cutter in bitumen, $ per litre of additive 0.25 

Incorporate adhesion agent in bitumen, $ per litre of additive 1.35 

Heat and spray binder, $ per litre 0.30 

Load, haul, spread and roll aggregate, $ per cubic metre 55.00 

Calculate the quantities, and estimate the total cost (in $) for the sprayed sealing work. In your costing, no allowances are required for establishment costs, or traffic control, etc.