a. Describe the different principles involved in the design of at-grade intersec

Question

a. Describe the different principles involved in the design of at-grade intersections and the different types
of at-grade intersections. Also, give an example of an appropriate location for the use of each type. b. A minor road intersects a multilane divided highway at 90° forming a T intersection. The speed limits on
the major and minor roads are 55 and 35 mi/h, respectively. ? Design the minimum sight distance required for a single-unit truck on the minor road to depart from
a stopped position and turn left onto the major road. Discuss additional consideration should be
given to the sight distances computed for the design vehicle crossing the intersection. ? For the design determine the sight distance required by the minor-road vehicle to safely complete a
right turn onto the major road. ? Discuss the changes if the intersection is an oblique intersection with an acute angle of 35°.

Explanation / Answer

a)

Principal involned in design at grade intersecion

Various forms of intersection at-grade

Example:this type of intersection adopted only on road intersection with very low traffic volume

2. Channelized intersection

Example:this method reduce total conflict area then it reduce possiblites of accident he ve this method is used at high volume traffic

3.Rotary intersection

Example: the main object of this method is to eliminate necessity of shopping and reduce conductor area

b)

Sight distance is the minimum distance on the road available to a driver of certain height to have visibility of moving or stationary objects.

Here the the total sight distance for the driver on the minor road is the sum of sight distance of the two vehicle

That's

SD=(v1t+v12/2f1g ) +(v2t+v22/2f2g)

Here v1=35×5÷18m/sec. ,V2=55×5÷18m/sec. ,f1=.4 and f2=.37 acc to Irc

Then SD=106.74meter

In case of intersection angle 35 degree the SD =106.74 is safe because in this case the distance is more available due to slope at intersection

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.