Transportation and Geometrics

Question 1

What does PT stand for, where is is and what is it?

Question 2

what is jam density and what is the equation for it?

Question 3

what is free flow speed and how is it calculated

Question 4

how do you fins capacity of a highway section?

Answer 4

by determining the peak of the speed-flow or flow density curves - qCAP

Question 5

In a horizontal curve formulas what point is PC also called?

Answer 5

BC, begining of curve equal point of curve

Question 6

In a horizontal curve formulas what point is PC also called?

Answer 6

BC, beginning of curve = point of curve PC

Question 7

In a horizontal curve formulas what point is PT also called?

Answer 7

EC, ending point of curve = PT point of tangenet

Question 8

In a horizontal curve formulas what point is PT also called?

Answer 8

EC, ending point of curve = PT point of tangent

Question 9

What is PI ?

Answer 9

point at which the two tangents meet

Question 10

For intersection of freeway ramp terminals with aerial crossroads geometrical design, what type of vehicle would be a good design vehicle?

Answer 10

Interstate semitrailer

Question 11

For intersection of freeway ramp terminals with aerial crossroads geometrical design, name 3 types of vehicles that would be bad design vehicle?

Answer 11

passenger car, Single unit Truck, City transit bus

Question 12

Define headway

Answer 12

the time interval between two consecutive vehicles

Question 13

Define Saturation Headway

Answer 13

is the headway when traffic volume reaches the freeway capacity

Question 14

Define Freeway Capacity

Answer 14

this is the maximum # of vehivles that can pass through the freeway section in *1 hour (check 1 hour)

Question 15

Equation for Station of PT?

Answer 15

Sta PT= sta PC + L ( not given)

Question 16

Equation for station of PC

Answer 16

Sta PC = Sta PI -T

Question 17

How do you convert D° M’ S’’ to just degrees

Answer 17

D°+ (M/60)+(S/3600)

Question 18

how to convert feet to a station

Answer 18

feet/ 100 = X.00
convert “.” to “+”

Question 19

Equation for station PVC?

Answer 19

Sta PVC = Sta PVI - (L/2)

Question 20

PVC station + Xm =?

Answer 20

The station of the point of max elevation on the vertical curve

Question 21

what is an equation of the point at the same horizontal distance as PVC but on the back tangent line*

Answer 21

=PVC elevation + g1 (L)

Question 22

what is The vertical distance from the previous point to PVT, and the equation

Answer 22

vertical distance of Tangent outset = Y

y=((g2-g1)/2L)*L^2

Question 23

how to find the elevation of PVT given y and***

Question 24

using the Curve elevation equation, where is the maximum curve elevation?

Answer 24

where X = Xm

Question 25

for horizontal curves what does M represent?