CE 7670: Advanced Traffic Signal Systems Tapan K. Datta, Ph.D., P.E. Winter 2003

CE 7670: Advanced Traffic Signal Systems

Tapan K. Datta, Ph.D., P.E.

Winter 2003

Probability of Failure Method If (x-1) vehicles cross the stop bar

during a time equal to G – (K1 + K2) then the average minimum headway between the vehicle is given by: Avg. Min. headway = time/volume, or G – K x-1

Where K = K1 + K2

K1 = starting delay of the platoon K2 = time required for last vehicle to cross G = green plus amber time D = constant departure headway x = number of departures G = (x-1) D + K, or, G = x D + K - D

Probability of Failure Method to Calculate Cycle Length

Probability of Failure Method to Calculate Cycle Length

Assume critical lane volume = V

Sum of hourly critical lane volume (V) for all phases = total critical lane volume per hour

V = 3600

C* X =

3600

C

G - (K-D)*

D

Where: C = G = number of phases

= 3600 CCD

3600 (K-D)

CD-

K = lost time = K1 + K2

G = green plus amber time D = constant departure headway x = number of departures

V = 3600

C* X X =

[ G – (K – D)]

DWhere:

V = 3600

C*

C - (K-D)

D[ ]

V (for = 3) = 3600* 3(6-2)

C* 2

Say K = K1+ K2 = 6 sec D = 2 sec

1800 -

21600

C1800 - =

V (for = 4) = 3600* 4(6-2)

C* 21800 -

28800

C1800 - =

As V approaches 1800 vph, C approaches infinity

C = 3600 (K-D)

3600 – D V Based on uniform arrival

Poisson Arrival

Based on random arrivals

P (x+1) =x+1

m(x+1) e-m

(x + 1)!

Where:m = average arrival per cycle = V

3600/C

Signal Phasing Design

Through traffic shared with right-turn traffic Solid green followed by yellow and red

Left-turn traffic: Lead left-turn Protected

• Green left arrow followed by yellow and red Protected/Permissive

• Green left arrow followed by solid green • Then yellow and red

Left-turn traffic: Lag left-turn Permissive/Protected

• Solid green followed by green left arrow• Then yellow and red

Split Phasing• When one approach has much higher volume than

the opposing approach, only one direction traffic (including left-turn) is allowed to proceed in a protected manner, and then the opposing traffic

The Texas Approach

Trap Problem: Using protected-permitted and lead-lag phasing at the same time leads a vehicle to be trapped

Solution: Waiting left-turner is able to see the ball indications which clear at the same time as opposing through traffic, and thus drivers do not make false assumptions

The Texas Concept Having at least two signal heads for through traffic in addition to five-section protected-

permitted left-turn signal Reducing the visibility of circular indications of five-section left-turn signal so that they

are readily visible by left-turners Modifying the restricted-visibility indications so that they continue to display a circular

green to left-turners through the opposing left-turn movement’s lagging protected phase, and displaying the amber for the permitted left-turn only when the amber is on for opposing through traffic also

The Florida Recommendations

Protected/Permissive left-turn phasing should be provided in all intersection approaches

Protected only left-turn should be provided if: Double left-turn only lanes are operating Intersection geometric compels to do so Poor sight distance to opposing traffic Speed limit of opposing traffic is higher than

45mph Number of left-turn head-on crashes exceeds 6

per year


Permissive/Protected left-turn phasing should be limited and restricted to the following situations: T-intersections where U-turns are prohibited 4-way intersections where the opposing approach

has prohibited left-turns or protected only left-turn phasing

4-way intersections where the left-turn volumes from opposing approaches do not substantially differ throughout the various time periods of a normal day


Split phasing can be effectively used when: Opposing approaches are offset to an extent that

simultaneous left-turns from opposing directions would be impossible or hazardous

Left-turn volumes are extremely heavy on opposing approaches and both are nearly equal to the adjacent through movement critical lane volume

Left-turn volume is extremely heavy on an approach that does not include a separate left-turn lane

Drivers are permitted to turn left from more than one lane and also to use right-most left-turn lane as a through lane.

The Kentucky Recommendation

Protected/Permissive is the preferable method because of savings in time compared to protected only phasing

Protected/Permissive should not be used if the following conditions exist:

• Approach speed > 45mph• Protected only is currently in use and speed limit is over 35

mph• Left-turn movement must cross three or more opposing

through lanes• Intersection geometrics force the left-turn lane to have a

separate signal head• Double left-turn only lanes on the approach• Left-turn head-on crashes is 4 or more per year• Potential left-turn problem exists documented by a traffic

conflict study• A sight distance problem exists

Lane Configuration for the Intersection of Gratiot Avenue and 23 Mile Road

23 Mile RoadG

rati

ot

N

Future AM Peak Hour Traffic Volumes for Gratiot Avenue and 23 Mile Road

Approach Volume = 1,295vph

Approach Volume = 651vph

N

23 MILE ROAD

GR

AT

IOT

AV

EN

UE

340+11=351 726

Approach Volume = 1,257vph

Approach Volume = 558vph

Total Intersection Volume

= 3,761 vph

498+6=504

47

298 156+5=161

728+5=733

180

99

100361+4= 365

187+10=197

Phasing Plan for Gratiot and 23 Mile Road

1 2 3 4 5 6

Example

470

100 300

N

25

270 30500100

475100 300

N

25

270 30500100

475760

940

380

100

100

200180

140 100

280

180

5 x 5 lane roadFour phase signal timing plan

1 2 3 41 2 3 4

Critical lane volumesV1 = Max [(760+200)/2, (380+140)/2] = 480V2 = Max [180,100] = 180V3 = Max [(940+180)/2, (470+100)/2] = 560V4 = Max [280,100] = 280

Start by assuming a cycle lengthSay 90 seconds

Calculate ‘m’ for each phase

V3600/Cm=

m1= 4803600/90

= 12

m2= 1803600/90

= 4.5

m3= 5603600/90

= 14

m4= 2803600/90

= 7

Use Figure 7-3 to find the phase length ‘G’ for various percentages of failure

mPhase length ‘G’ for various % of failure

2 5 20 30 40

1 12 42 39 33 30 28

2 4.5 21 19 15 14 13

3 14 47 44 37 35 33

4 7 29 26 21 19 18

TOTAL CL 139 128 106 98 92

If the arrivals of cars are random Cycle length of 98 seconds has 30% of

failure Cycle length of 92 seconds has 40%

failure

Now assume a 100-second cycle length Calculate ‘m’ for each phase

V3600/Cm=

m1= 4803600/100

= 13.3

m2= 1803600/100

= 5.0

m3= 5603600/100

= 15.6

m4= 2803600/100

= 7.8

Use Figure 7-3 to find the phase length ‘G’ for various percentages of failure

mPhase length ‘G’ for various % of failure

2 5 20 30 40

1 13.3 44 41 35 33 31

2 5.0 23 21 17 15 14

3 15.6 51 48 41 37 35

4 7.8 31 29 23 21 20

TOTAL CL 149 139 116 106 100

If the arrivals of cars are random Cycle length of 106 seconds has 30% of

failure Cycle length of 100 seconds has 40%

failure

Comprehensive Example:Intersection of Rochester Road and E. Wattles Road,

Troy Michigan

N

RO

CH

ES

TE

R R

OA

D

Comerica Bank

Wendy’s Restaurant

Accent Florist

Kinko’sCopy Center

Merchant of Vino Beverage

Outlet

BlockbusterVideo Store

PapaRomano’s

Pizza

Ridley’sBakery

Cafe

E. WATTLES ROAD

Shell Gasoline

Station

Condition Diagram for Rochester Road and E. Wattles Road - Troy, Michigan

RIGHT LANE MUST TURN RIGHT Sign

NO TURN ON RED Sign

Street Name Signs

NO TURN ON RED Sign

SPEED LIMIT 45 Sign

SPEED LIMIT 45 Sign

ON

LY

ON

LY

SPEED LIMIT 40 Sign

SPEED LIMIT 40 Sign

ONLY

ONLY

ONLY

ONLY

43’

41’

7’ 8’ 34’

3’

9’ 6’

12’ 12’ 12’ 12’ 13’ 13’

13’ 11’ 13’13’ 14’

176’

24’ 65’ 138’ 22’

8’

108’

20’

173’

38’


NO TURN ON RED Sign

ON

LY

ON

LY

ON

LY

ON

LY

NO TURN ON RED Sign


TO I-75 Sign

13’12’

19’

12’

12’

14’

11’

17’

ON

LY

ON

LY

ONLY

ONLY

Pavement markingsvery faded

75’

WESTBOUND E. WATTLES ROAD

SOUTHBOUND ROCHESTER ROAD

EASTBOUND E. WATTLES ROAD

NORTHBOUND ROCHESTER ROAD

N

Traffic Volumes for Rochester Road and East Wattles Road - Troy, Michigan

PM Peak 5-6 PM

467 554 116

103 1135 300

241

568

90

116

331

130

Midday Peak Noon- 1 PM

56 497 98

91 855 204

155

225

141

76

242

162

AM Peak 8-9 AM

73 678 109

103 616 150

76

258

103

70

567

191

Phasing Diagram for Existing Condition Phasing Diagram for Existing Condition

E-WThrough/Right

Phase

1

E-WLeft-Turn

Phase

2

N-SThrough/Right

Phase

34

N-SLeft-Turn

Phase

Capacity Analysis For Existing Traffic Conditions

CYCLELENGTH

(SEC)

APPROACH APPROACHLOS

INTERSECTIONLOS

INTERSECTIONDELAY

(SEC/VEH)Northbound ESouthbound DEastbound F

100

Westbound C

E 48.8

Northbound ESouthbound DEastbound F

90

Westbound C

E 48.3


80

Westbound C

E 48.4

Crash Data

TYPE OFCRASH AVERAGE NUMBER OF

CRASH 1997 1998 CRASHES PER YEAR

Rear-End 46 33 39.5Angle Intersection 1 2 1.5

Left-Turn Head-On Inter.26 33 29.5

Sideswipe

2 3 2.52 4 3

Other7 6 6.5

INJURIES 15 12 13.5TOTAL PER YEAR 87 82 84.5

YEAR

Angle Driveway

Left-Turn Head-On Dway.

3 1 2

Collision Diagrams for 1997 and 1998

LEGEND FOR COLLISION DIAGRAMS

Rear-End

Backed Into

Head On

Angle

Left-TurnHead-On

Sideswipe

Fixed Object

Parked Vehicle

Pedestrian

Other

Injury

Fatality

*

Collision Diagram for Rochester Road and E. Wattles Road for 1997

N

E. Wattles Road

Ro

ches

ter

Ro

ad

5/21

5/25 10/163/15

3/6

5/17

1/29

4/3

9/8

8/2

8/15

9/3

5/30

11/11

5/27

6/23

7/15

8/20

7/1

4/9

12/9

9/12

9/18

10/23

2/1211/1

12/30

8/13

1/30

4/21

4/29

10/16 1/8

10/11

3/9

7/28

4/163/29

2/14

4/12

5/24

7/29

1/16

10/22 6/10

9/10

4/7

2/24

5/5

3/28

5/15

6/3

9/41/29

7/8

* 8/24

6/25 6/6

7/14

5/5

11/181/17

10/19

12/22

6/20

5/2

4/7

12/24/23

7/17/19

2/2812/20

5/23

6/177/14

10/6

3/14

4/16

11/1212/81/19

9/2012/30

6/28

8/292/28

12/19

10/29

E. Wattles Road

N

Ro

ches

ter

Ro

ad

Collision Diagram for Rochester Road and E. Wattles Road for 1998

5/27

6/11

3/297/17

6/1

12/29

12/20 10/9

4/30 10/157/158/17

7/30

4/10

12/9

10/37/158/30

2/112/14

9/29

3/6

11/26

7/10

8/10

7/9

4/14

7/22

12/21

3/17

5/22

8/9

7/7

5/13

5/11

12/10

6/11

1/7

6/1

7/29

6/25

1/17

2/23

3/10

6/29

9/30

9/26

6/20

6/30

1/73/3

10/8 10/30

9/2 3/19

8/3

6/22

1/30

6/30

10/211/20

9/203/20

3/271/4

2/1710/1

2/27

6/9

1/19

4/22

9/156/24

12/23

6/30

11/9

10/1711/20

11/20

1/2 11/9 3/27

Phasing Diagram for Modified Signal Timing

E-WThrough/Right

Phase

1

E-WLeft-Turn and SB Right Turn

Phase

2

N-SThrough/Right

Phase

3 4

N-SLeft-Turn and

E-W Right Turn Phase

Signal Timing Modifications to Existing Traffic Conditions

Include right turn phase with exclusive left turn phase for:

Southbound approach

Eastbound approach

Westbound approach

Capacity Analysis For Existing Traffic Conditions with Signal Timing

Modifications

CYCLELENGTH

(SEC)


INTERSECTIONLOS

INTERSECTIONDELAY

(SEC/VEH)Northbound ESouthbound DEastbound F

100

Westbound C

E 47.1


90

Westbound C

E 44.6


80

Westbound C

E 46.9

Cycle length using Webster’s Equation

Existing Condition

C = 1.5 L + 51.0 - y

y1 = (568 + 90)/ (1800 * 2) = 0.188 or = (331 + 116)/ (1800 * 2) = 0.124

y2 = 241/1000 = 0.241 or = 130/1000 = 0.130

y3 = (1135 + 300)/(1800 * 2) = 0.40 or = (554 + 467)/(1800 * 3) = 0.189

y4 = 103/1000 = 0.103 or = 116/1000 = 0.116

Y = 0.188 + 0.241 + 0.40 + 0.116 = 0.945

C = 1.5 * (2 * 4) + 5 / ( 1-0.945) = 309 second cycle length

Calculate Splits

Assume Cycle Length = 90 seconds Split = Green interval + Yellow interval + All-red

interval

1 split = 0.188 * 90/ 0.945 = 18 sec

2 split = 0.241 * 90/ 0.945 = 23 sec

3 split = 0.40 * 90/ 0.945 = 38 sec

4 split = 0.116 * 90/ 0.945 = 11 sec

Calculate Clearance IntervalCI = t + v

2(a ± Gg)

w + L v+

Speed Limit on Rochester Road = 45 mph = 66 fpst = 1 sec, a = 10 ft/sec/sec

CINS = 1 + 66/(2 * 10) + (110 + 20)/ 66 = 4.3 sec + 2.0 sec = 6.3 seconds

Speed Limit on E. Wattles Road = 40 mph = 58.67 fpst = 1 sec, a = 10 ft/sec/sec

CIEW = 1 + 58.67/(2 * 10) + (116 + 20)/ 58.67 = 3.9 sec + 2.3 sec = 6.2 seconds

Signal Timing Plan

G = 12 sec G =18 sec G = 32 sec G = 6 secA = 4 sec A = 3 sec A = 4 sec A = 3 secR = 74 sec R = 69 sec R = 54 sec R = 81 sec AR = 2 sec AR = 2 sec AR = 2 sec AR = 2 sec

E-WThrough/Right

Phase

1

E-WLeft-Turn

Phase

2

N-SThrough/Right

Phase

34

N-SLeft-Turn

Phase

Proposed Improvements High right turn volume for

Northbound Rochester Road Include exclusive right turn lane using

existing pavement width

N

RO

CH

ES

TE

R R

OA

D

Comerica Bank

Wendy’s Restaurant

Accent Florist

Kinko’sCopy Center

Merchant of Vino Beverage

Outlet

BlockbusterVideo Store

PapaRomano’s

Pizza

Ridley’sBakery

Cafe

E. WATTLES ROAD

Shell Gasoline

Station

Proposed Intersection Diagram for Rochester Road and E. Wattles Road - Troy, Michigan


NO TURN ON RED Sign

Street Name Signs

NO TURN ON RED Sign

SPEED LIMIT 45 Sign

SPEED LIMIT 45 Sign

ON

LY

ON

LY

SPEED LIMIT 40 Sign

SPEED LIMIT 40 Sign

ONLY

ONLY

ONLY

ONLY

43’

41’

7’ 8’ 34’

3’

9’ 6’

11’ 11’ 11’ 11’ 15’ 15’

11’ 10’ 10’12’ 10’

176’

24’ 65’ 138’ 22’

8’

108’

20’

173’

38’


NO TURN ON RED Sign

ON

LY

ON

LY

ON

LY

ON

LY

NO TURN ON RED Sign


TO I-75 Sign

12’11’

11’

11’

11’

11’

10’

11’

ONLY

ONLY

ON

LY

ON

LY

ONLY

ONLY

11’

11’

11’


75’

Phasing Diagram for Proposed Improvements with Laneage Modification

E-WThrough/Right

Phase

1

E-WLeft-Turn and

N-S Right Turn Phase

2

N-SThrough/Right

Phase

3 4

N-SLeft-Turn and

E-W Right Turn Phase

Capacity Analysis With Proposed Improvements- Laneage Modifications

CYCLELENGTH

(SEC)


INTERSECTIONLOS

INTERSECTIONDELAY

(SEC/VEH)Northbound DSouthbound CEastbound E

100

Westbound C

D 32.9

Northbound ESouthbound CEastbound E

90

Westbound C

D 38.0

Northbound ESouthbound CEastbound E

80

Westbound C

D 39.4

Traffic Signal Warrants

Traffic signals should not be installed unless one or more of the warrants are met

Engineering studies should be performed and compared with warrants analysis should consider effects of right turn

volumes• proportion subtracted from volumes should be

based on engineering judgement

Warrants for Signalized Intersections

Warrant 1: Minimum Vehicular Volume

Number of lanes for movingtraffic at each approach

Vehicles per hour onmajor street

(total of both approaches)

Vehicles per hour on highervolume minor street approach

(one direction only)

Major Street Minor Street

1 1 500 150

2 or more 1 600 150

1 2 or more 500 200

2 or more 2 or more 600 200

satisfied when the volumes given in the table exits

• on major street and

• on the higher volume minor street

• for any 8 hours of an average day

when 85th percentile speed of major street exceeds 40 mph

• 70 % of the requirements may be used

Warrant 2: Interruption of Continuous Traffic

Number of lanes for movingtraffic at each approach

Vehicles per hour onmajor street

(total of both approaches)

Vehicles per hour on highervolume minor street approach

(one direction only)

Major Street Minor Street

1 1 750 752 or more 1 900 75

1 2 or more 750 100

2 or more 2 or more 900 100

Warrant Applies where traffic volume on major street is so high that traffic on minor intersecting street experiences excessive delay.

satisfied when, the volumes given in the table exists on the major street

on the higher-volume minor street

the signal installation will not seriously disrupt progressive traffic

flow for each of any 8 hours of an average day

when 85th percentile speed of major street exceeds 40 mph

• 70 % of the requirements may be used

Warrant 3: Minimum Pedestrian Volume

Warranted where the pedestrian volume crossing the major intersection or mid-block location during an average day is: 100 or more for each of any four hours, or 190 or more in any one hour

The pedestrian volume of the major street may be reduced as much as 50% of the values given above when predominant pedestrian crossing speed is below 3.5 fps

Warrant 4: School Crossing warranted at an established school crossing when a

traffic engineering study of the frequency and adequacy of gaps in a traffic stream shows that the number of adequate gaps in the traffic stream during the period when the children are using the crossing is less than the number of minutes in the same period.

T = 3 + + Fwidth of street

4

Where F = Number of children per group - 1 (2)

5 ( )

A minimum of 50 children should be utilizing the crossing before applying this warrant

Warrant 5: Progressive Movement

Warranted in order to maintain proper grouping of vehicles and effectively regulate group speed

The warrant is satisfied when: on a one-way street or a street which has predominantly unidirectional traffic on a two-way street

• adjacent signals do not provide the necessary degree of platooning and speed control,and the proposed and adjacent signals could constitute a progressive signal system

Should be based on the 85% speed unless study indicate other speed is more desirable

Warrant 6: Accident Experience

This warrant is satisfied when: Adequate trial of less restrictive remedies with

satisfactory observance and enforcement has failed to reduce the accident frequency; and

Five or more reported accidents, of types susceptible to correction by traffic signal control, have occurred within a 12-month period,and

There exists a volume of vehicular and pedestrian traffic not less than 80 percent of the requirements specified in the warrants

Any signal installation will not seriously disrupt progressive traffic now.

N

LEGENDRear-End

Backed Into

Head On

Angle

Left-TurnHead-On

Sideswipe

Fixed Object

Parked Vehicle

Pedestrian

Other

Injury

Fatality

**

Collision Diagram for Five Mile Road and Middlebelt Road for 1999

Five Mile Road Mid

dleb

elt

Roa

d

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20 21

22

23

24

25

26

2728

29

30

31

32

33

34

35

36

37

38

39

40

41

N

LEGENDRear-End

Backed Into

Head On

Angle

Left-TurnHead-On

Sideswipe

Fixed Object

Parked Vehicle

Pedestrian

Other

Injury

Fatality

**

Wyo

min

g A

ven

ue

McNichols Road

Collision Diagram for Wyoming Avenue and McNichols Road for 1997

01/0301/0301/0401/04

01/0601/06

01/12

01/13

01/13

01/16

01/21

01/23

01/2601/26

01/2701/27

02/01

02/14

02/14

02/17

02/20

03/06

03/8

03/21

04/03

04/04

04/09

04/24

04/27

05/05

05/06

05/22

05/22

05/23

06/06

06/09

06/15

06/15

06/18

06/19

06/20

06/20

07/0307/0607/08

07/14

07/14

07/14

07/15

07/27

08/12

08/17

08/17

08/27

08/31

09/03

09/09

09/10

09/13

09/20

09/25

09/27

09/29

10/01

10/12

10/21

10/30

10/31

11/05

11/05

11/0711/1011/10

11/14

11/16

11/17

11/20

11/23

11/25

*11/28

**11/28 12/04

**12/04

12/08

12/19

12/2212/2412/31

Warrant 7: Systems Warrant

A major route has one or more of the following characteristics: It is part of the street or highway system that

serves as the principal network for through traffic flow;

It includes rural or suburban highways outside of, entering, or traversing a city;

It appears as a major route on an official plan, such as a major street in a transportation study

Warrant 8: Combination of Warrants

Signals may be justified where no single warrant is satisfied but where Warrants 1 and 2 are satisfied to the extent of 80 percent or more of the stated values

Warrant 9: Four Hour Volumes

Satisfied when, each of any four hours of an average day the plotted points representing the vehicles per hour on the major street (total of both approaches) and the corresponding vehicle per hour on the higher volume minor street approach (one direction only) all fall above the curve in Figure 4-3 for the existing combination of approach lanes

85 percentile speed exceeds 40 mph, the four hour volume requirement is satisfied when the plotted points referred to fall above the curve in figure 4-4 for the existing combination of approaches.

Warrant 10: Peak Hour Delay Satisfied when these conditions exist for

one hour of an average weekday Total delay experienced by traffic on a side street

controlled by STOP sign equals or exceeds four vehicle-hours for a one-lane approach and five vehicle-hours for a two-lane approach, and

The volume on the side street approach equals or exceeds 100 vph for one moving lane of traffic or 150 vph for two moving lanes, and

The total entering volume services during the hour equals or exceeds 800 vph for intersection with four (or more) approaches or 650 for intersections with three approaches

Warrant 11: Peak Hour Volume

Satisfied when, the plotted point representing the vph the major street (total of both approaches) and the corresponding vehicles per hour of the higher volume minor street approach (one direction only) for one hour of an average day falls above the curve in Figure 4-5 for the existing combination of approach lanes

When the 85th percentile speed exceeds 40mph, peak hour volume requirement is satisfied when the plotted point falls above the curve in figure 4-6 for the existing combination of approach lanes

Example: Main Road with existing driveway

12-hour traffic counts Major Street is Dequindre Road (N-S)

Has 2 NB lanes and 2 SB lanes Speed limit = 45 mph 85th percentile speed = 47 mph

Minor Street is Beaumont Hospital driveway approach One right turn lane and one left turn lane

N

Figure 3b. Existing Condition Diagram of Study Area

B B

68’

335’

168’

EmergencySign

449’

96’

10’ 12’ 4’12’ 13’

KeepRight

280’

10’ 12’ 11’ 13’ 12’

Overhead Sign

Junction 59 and

VFW MemorialHighway Sign

Speed Limit45 Sign

121’

A A

DE

QU

IND

RE

RO

AD

15’ 14’ 11’ 11’

BEAUMONT HOSPITALNORTHERN DRIVEWAY

ST

OP

ST

OP

StopSign

10’9’

17’

Right Lane Ends Sign

Do Not Pass Sign

N

Figure 3b. Existing Condition Diagram of Study Area

B B

68’

335’

168’

EmergencySign

449’

96’

10’ 12’ 4’12’ 13’

KeepRight

280’

10’ 12’ 11’ 13’ 12’

Overhead Sign

Junction 59 and

VFW MemorialHighway Sign

Speed Limit45 Sign

121’

A A

DE

QU

IND

RE

RO

AD

15’ 14’ 11’ 11’

BEAUMONT HOSPITALNORTHERN DRIVEWAY

ST

OP

ST

OP

StopSign

10’9’

17’

Right Lane Ends Sign

Do Not Pass Sign

On Dequindre Road South of driveway

Beaumont Hospital and the proposed signal

location at the driveway

12-hour Traffic Volumes

TIME

DEQUINDRE ROAD (TOTAL OF NB AND SB

DIRECTIONS OF TRAFFIC) VPH

MINOR STREET APPROACH VPH

7:00-8:00 AM 615 + 821 = 1,436 127

8:00-9:00 AM 501 + 743 = 1,244 51

9:00-10:00 AM 423 + 596 = 1,019 43

10:00-11:00 AM 452 + 529 = 981 71

11:00-12:00 PM 604 + 639 = 1,243 67

12-00-1:00 PM 539 + 778 = 1,317 116

1:00-2:00 PM 658 + 683 = 1,341 79

2:00-3:00 PM 713 + 632 = 1,345 127

3:00-4:00 PM 1,058 + 742 = 1,800 325

4:00-5:00 PM 1,272 + 586 = 1,858 275

5:00-6:00 PM 1,245 + 601 = 1,846 158

6:00-7:00 PM 694 + 481 = 1,175 121

Warrant #1 Requirements (for 8 hours): Can use the 70% reduction, since

85th percentile speed > 40 mph Major Street (total of both approaches)

with 2 or more lanes • 600* 0.70 = 420 vph

Minor Street (one approach) with 2 or more lanes• 200 * 0.70 = 140 vph

TIME




Warrant Met = Warrant No.1

Volume Criteria (Major Street = 420, Minor Street = 140)

7:00-8:00 AM 615 + 821 = 1,436 127

8:00-9:00 AM 501 + 743 = 1,244 51

9:00-10:00 AM 423 + 596 = 1,019 43

10:00-11:00 AM 452 + 529 = 981 71

11:00-12:00 PM 604 + 639 = 1,243 67

12-00-1:00 PM 539 + 778 = 1,317 116

1:00-2:00 PM 658 + 683 = 1,341 79

2:00-3:00 PM 713 + 632 = 1,345 127

3:00-4:00 PM 1,058 + 742 = 1,800 325

4:00-5:00 PM 1,272 + 586 = 1,858 275

5:00-6:00 PM 1,245 + 601 = 1,846 158

6:00-7:00 PM 694 + 481 = 1,175 121

Warrant No. 1 is not met

Warrant #2 Requirements (for 8 hours): Can use the 70% reduction, since

85th percentile speed > 40 mph Major Street (total of both approaches)

with 2 or more lanes • 900* 0.70 = 630 vph

Minor Street (one approach) with 2 or more lanes• 100 * 0.70 = 70 vph

TIME




Warrant Met = Warrant No. 2


7:00-8:00 AM 615 + 821 = 1,436 127

8:00-9:00 AM 501 + 743 = 1,244 51

9:00-10:00 AM 423 + 596 = 1,019 43

10:00-11:00 AM 452 + 529 = 981 71

11:00-12:00 PM 604 + 639 = 1,243 67

12-00-1:00 PM 539 + 778 = 1,317 116

1:00-2:00 PM 658 + 683 = 1,341 79

2:00-3:00 PM 713 + 632 = 1,345 127

3:00-4:00 PM 1,058 + 742 = 1,800 325

4:00-5:00 PM 1,272 + 586 = 1,858 275

5:00-6:00 PM 1,245 + 601 = 1,846 158

6:00-7:00 PM 694 + 481 = 1,175 121

Warrant No. 2 is met

Warrant # 9 Requirement (4 hours) Use Figure 4-4 since 85th percentile

speed exceeds 40 mph lower threshold volume for a minor

street approach with two or more lanes is 80 vph, when the traffic volumes on the major street exceed 875 vph.

TIME






7:00-8:00 AM 615 + 821 = 1,436 127

8:00-9:00 AM 501 + 743 = 1,244 51

9:00-10:00 AM 423 + 596 = 1,019 43

10:00-11:00 AM 452 + 529 = 981 71

11:00-12:00 PM 604 + 639 = 1,243 67

12-00-1:00 PM 539 + 778 = 1,317 116

1:00-2:00 PM 658 + 683 = 1,341 79

2:00-3:00 PM 713 + 632 = 1,345 127

3:00-4:00 PM 1,058 + 742 = 1,800 325

4:00-5:00 PM 1,272 + 586 = 1,858 275

5:00-6:00 PM 1,245 + 601 = 1,846 158

6:00-7:00 PM 694 + 481 = 1,175 121


Warrant # 11 Requirement (one hour): Use Figure 4-6 since 85th percentile

speed of the major street exceeds 40 mph lower threshold volume for a major

street approach with two lanes is 100 vph when the major street volume is greater than 1200 vph.


TIME






7:00-8:00 AM 615 + 821 = 1,436 127

8:00-9:00 AM 501 + 743 = 1,244 51

9:00-10:00 AM 423 + 596 = 1,019 43

10:00-11:00 AM 452 + 529 = 981 71

11:00-12:00 PM 604 + 639 = 1,243 67

12-00-1:00 PM 539 + 778 = 1,317 116

1:00-2:00 PM 658 + 683 = 1,341 79

2:00-3:00 PM 713 + 632 = 1,345 127

3:00-4:00 PM 1,058 + 742 = 1,800 325

4:00-5:00 PM 1,272 + 586 = 1,858 275

5:00-6:00 PM 1,245 + 601 = 1,846 158

6:00-7:00 PM 694 + 481 = 1,175 121

Example: Existing Road with Proposed Driveway

Proposed developments may want a traffic signal installed at a driveway location

Traffic impact analysis using ITE “Trip Generation” manual Provides rates to predict number of trips generated

by development Provides rates only for peak hours On this basis, only Warrant No. 11 (Peak Hour

Volumes) is applicable

However, for Shopping Center Developments ITE published hourly percentages (12 hours) for

variation in traffic throughout:• Typical weekday• Typical weekend days

The rates can be used to predict traffic for a twelve hour period Can perform a warrant study based on other

warrants, instead of only Warrant No. 11

For example: Number of trips predicted exiting the driveway

approach during the PM peak hour (5-6 PM) = 214 vph

Table 1 shows that from 5-6 PM The % of exiting traffic = 11%

Use this proportion, along with the percent exiting trips for the remaining hours of the day To calculate the predicted # of exiting trips for the

rest of the day

The percent of exiting trips at 10-11 AM is 6.5% Average weekday < 100,000 sq. ft. of GLA

Thus, the predicted # of exiting trips (x10-11) will be

21411

Thus, X10-11 = 126 vph6.5

=X10-11

21411

Thus, X11-12 = 163 vph8.4

=X11-12

Similarly, for the remaining hours:

21411

Thus, X12-1 = 160 vph8.2

=X12-1

21411

Thus, X1-2 = 146 vph7.5

=X1-2

And so on. Results shown in following table

SB WESTERN DRIVEWAY APPROACH VOLUMES (VPH)

% of 24 Hour Volume Expected Traffic

Volume

6.5 126

8.4 163

8.2 160

7.5 146

7.8 152

9.5 185

10.4 202

11.0 214

8.3 161

5.3 103

4.3 84

TIME

M-29 TRAFFIC VOLUMES (TOTAL OF EB AND WB


(Source- 1999 MDOT Count)

10:00-11:00 AM 597

11:00-12:00 PM 642

12-00-1:00 PM 900

1:00-2:00 PM 910

2:00-3:00 PM 831

3:00-4:00 PM 878

4:00-5:00 PM 958

5:00-6:00 PM 994

6:00-7:00 PM 983

7:00-8:00 PM 889

8:00-9:00 PM 684

9:00- 10:00 PM 1.8 35

Now, perform a warrant analysis

12-hour traffic counts on major road and predicted 12-hour volumes for driveway approach

Major Street is M-29 Road (E-W) Has 1EB lane and 1 WB lane with proposed

center lane for left turns Speed limit = 45 mph

Minor Street is proposed retail center driveway approach Two lanes

Proposed signal location for commercial development ,

across from existing driveway

Existing driveway and M-29

12-hour traffic volumes (Existing volumes on major street and predicted

volumes on minor street)SB WESTERN DRIVEWAY APPROACH

VOLUMES (VPH) TIME




% of 24 Hour Volume Expected Traffic

Volume

10:00-11:00 AM 597 6.5 126

11:00-12:00 PM 642 8.4 163

12-00-1:00 PM 900 8.2 160

1:00-2:00 PM 910 7.5 146

2:00-3:00 PM 831 7.8 152

3:00-4:00 PM 878 9.5 185

4:00-5:00 PM 958 10.4 202

5:00-6:00 PM 994 11.0 214

6:00-7:00 PM 983 8.3 161

7:00-8:00 PM 889 5.3 103

8:00-9:00 PM 684 4.3 84

9:00-10:00 PM 488 1.8 35

Warrant #1 is metWarrant Met =

TIME



(Source-1999 MDOT Count)

SB WESTERN

DRIVEWAY APPROACH

VOLUME (VPH)

Warrant No. 1 Volume Criteria

(Major Street = 420, Minor Street = 140)

10:00-11:00 AM 597 126

11:00-12:00 PM 642 163

12-00-1:00 PM 900 160

1:00-2:00 PM 910 146

2:00-3:00 PM 831 152

3:00-4:00 PM 878 185

4:00-5:00 PM 958 202

5:00-6:00 PM 994 214

6:00-7:00 PM 983 161

7:00-8:00 PM 889 103

8:00-9:00 PM 684 84

9:00-10:00 PM 488 35


TIME




SB WESTERN DRIVEWAY APPROACH

VOLUME (VPH)



10:00-11:00 AM 597 126

11:00-12:00 PM 642 163

12-00-1:00 PM 900 160

1:00-2:00 PM 910 146

2:00-3:00 PM 831 152

3:00-4:00 PM 878 185

4:00-5:00 PM 958 202

5:00-6:00 PM 994 214

6:00-7:00 PM 983 161

7:00-8:00 PM 889 103

8:00-9:00 PM 684 84

9:00-10:00 PM 488 35


TIME





VOLUME (VPH)



10:00-11:00 AM 597 126

11:00-12:00 PM 642 163

12-00-1:00 PM 900 160

1:00-2:00 PM 910 146

2:00-3:00 PM 831 152

3:00-4:00 PM 878 185

4:00-5:00 PM 958 202

5:00-6:00 PM 994 214

6:00-7:00 PM 983 161

7:00-8:00 PM 889 103

8:00-9:00 PM 684 84

9:00-10:00 PM 488 35

Warrant # 11is not met Volumes on the major street do not meet requirements

Warrant Met =

TIME





VOLUME (VPH)



10:00-11:00 AM 597 126

11:00-12:00 PM 642 163

12-00-1:00 PM 900 160

1:00-2:00 PM 910 146

2:00-3:00 PM 831 152

3:00-4:00 PM 878 185

4:00-5:00 PM 958 202

5:00-6:00 PM 994 214

6:00-7:00 PM 983 161

7:00-8:00 PM 889 103

8:00-9:00 PM 684 84

9:00-10:00 PM 488 35

Left-Turn Phasing Warrants at Signalized Intersections

Warrants based on accidents 3-5 left-turn crashes/year N

LEGENDRear-End

Backed Into

Head On

Angle

Left-TurnHead-On

Sideswipe

Fixed Object

Parked Vehicle

Pedestrian

Other

Injury

Fatality

*

Kal

amaz

oo

Ave

nu

e

Burton street

Collision Diagram for Burton Street and Kalamazoo Avenue from April 1997- March 1998(12 months) before data

1

2

3

*4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

*25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

4142

N

LEGENDRear-End

Backed Into

Head On

Angle

Left-TurnHead-On

Sideswipe

Fixed Object

Parked Vehicle

Pedestrian

Other

Injury

Fatality

**

Kal

amaz

oo

Ave

nu

e

Burton street

Collision Diagram for Burton Street and Kalamazoo Avenue from April 1997- March 1998(12 months) before data

1

2

3

**4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

**25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

4142

Correctable LTHO crashes/year ≥ 4 LTHO crashes/ 2 years ≥ 6

Left-Turn Phasing Warrants at Signalized Intersections (ITE Journal April 1986)

Warrants based on volumes product of left turn and opposing volume

• 2 lane exceeds 30,000-50,0000• 4 lane exceeds 50,000-100,000

NUMBER OF OPPOSING

LANES

PRODUCT

1 ≥ 45,000

2 ≥ 90,000

3 ≥ 135,000

Warrants based on volumes sum of left turn and opposing volume

NUMBER OF OPPOSING

LANES

PRODUCT

1 ≥ 500

2 ≥ 900

3 ≥ 1000

Example

180 vph

590 vph

Product Rule:180 * 590 = 106,200For 2 opposing lanes, yes the left-turn phase is warranted (≥ 90,000)

Sum Rule:180 + 590 = 770For 2 opposing lanes, the left-turn phase is not warranted (< 900)

minimum left-turn hourly volumes- • exceeds 125 vph

minimum left-turn volume per cycle• exceeds 2 vehicles/cycle

Delay Analysis Maximum Allowable delay = 96 sec/veh

OR minimum total delay = 1.5 vehicle-hours

Other warrants geometric design- sight distance

inadequate signal system- progressive

movement/adjacent intersection phasing traffic conflict- exceeds 10-14/hour approach speed- of opposing traffic

exceeds 45 mph

Documents

CE 7670: Advanced Traffic Signal Systems Tapan K. Datta, Ph.D., P.E. Winter 2003