PE Transportation | Quizlet

Density =

flow rate [vphpl] / speed [mph]

Time mean speed

average speed of vehicles passing on a road

space mean speed

average speed of all vehicles occupying a given section of highway

spacing

distance between common points on successive vehicles [ft / veh]

headway

time between successive vehicles [sec / veh]. measured between common reference point

headway =

(3600 sec/hr) / v

headway =

spacing / S

jam density

density at 0 speed

AADT =

total yearly volume / 365

Directional Factor

peak dir hourly vol / 2 way hourly volume

to find density you must find:

LOS

Simple Hori Curve

arc of a circle is tangential

Compound Hori Curve

2 or more simple curves with varying radius

Reverse Hori Curve

2 circular arcs center opp.

Spiral Hori Curve

varying radius

Startup loss time for a traffic signal

2 sec

Pedestrian walk pace

3.5 ft/sec

? Freeway / Multilane Hwy

HCM Vol 2 Ch 12

? LOS

HCM

1 interchange means

2 ramps ( 1 on 1 off)

? weaving segment

HCM Vol 2 Ch 13

? freeway ramps

HCM Vol 2 Ch 14

? 2 lane smaller rural hwy

HCM Vol 2 Ch 15

? urban motorized veh and pedestrians bicycle transit

HCM Vol 3 Ch 18

LOS A means

performing well

? signalized intersection

HCM Vol 3 Ch 19

? 2 way side streets

HCM Vol 3 Ch 20

? All way stop controlled intersection

HCM Vol 3 Ch 21

? roundabout

HCM Vol 3 Ch 22

? ramp terminal and alternative intersections

HCM Vol 3 Ch 23

? off street ped faciities

HCM Vol 3 Ch 24

Want _ percentile traveling at or below speed limit

85th percentile

PHF used for _

signal design

vehicle miles of travel (VMT) is product of

product of ADT x length roadway [mi]

productions

leaving

attractions

arriving

? roadway safety management process

does site have a problem?

Part B Vol 1 on HSM is

? calculations for predictive methods

Part C Vol 2 on HSM is

? crash mod factors

Part D Vol 3 on HSM is

crash reduction capabilities

crash expected to change due to countermeasure

CRF

crash reduction factor

CMF

crash modification factor

if crashes in a single year use

VMT

if 6 months use

6 months V adjust

PDO

property damage only

EDPO

equivalent prpperty damage only

degree of curve

amount of interior angle req to cover a 100' distance along arc

interior angle

angle formed between PC to PI and PI to PT

PC =

PI - T

PT =

PC + L

horizontal sightline reaction time typically

2.5 sec

horizontal sightline deaccelration rate typically

11.2 ft/s^2

reaction time for signals

1 sec

HSO is calculated from

drivers position eyes to object

for sag curves most run _ equations and choose _

4, largest

typical angle headlight

1 degree

tailgate typically

2' off ground

morning part based on given

length

afternoon design speed and use

greenbook to find length

3 leg intersection has _ conflict points

9

4 leg intersection has _ conflict points

32

types of conflict points

diverging merging crossing

roundabout 3 leg has _ conflict points

6

roundabout 4 leg has _ conflict points

8

? roadside concepts

RDG Ch 3, 4

? barrier design

RDG Ch 5-9

? cross section

greenbook ch 4

? ADA

PROWAG

typical travel lane

12'. 9' min

asphalt shoulder slope

2-6%

gravel shoulder slope

4-6%

hwy shoulder

10'

pedestrain shoulder

4'

median shoulder typical

8'

minimum median

4'

sidewalk cross slope max

2%

max grade curb ramp

8.33%

? signal timing

HCM vol 3 ch 19

HMC vol 4 ch 31

MUTCD part 4

signal timing manual

? signal warrants

MUTCH part 4

STM ch 3,4

each mainline approach add up to _ phases

7

each sidestreet approach add up to _ phases

11

phase 1,3,5,7

left turn

phase 2,4,6,8

thru

if calculate a higher # than the given cycle _

subtract for the offset

? clearance int, signal head, pedestrian

MUTCD

minimum pedestrian walk allowance

7 sec

ped walk speed

3.5 ft/sec

? finding traffic signal components

HCM ch 19 equations

? signs pavement markings and temp traffic control

MUTCD

truck factor

1.2

pavement design life

20 years

dir factor

0.5 if =

signal head height

no less than 7 no more than 10'

PHF ranges

0.25 to 1

bearings are _ or less

90 degrees

1' =

60"

1 degree =

60'

azimuths

angle between north and line moving clockwise

dilemma zone xc _ x0

to fix:

>

increase yellow line, reduce speed

option zone x0_ xc

>