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Minimizing the impact of
latest MUTCD on
traffic signal operation
Presented by
Jose Guedes, T.E.
ITE 2015 Western District Annual Meeting
July 19-22, 2015
Las Vegas, Nevada
2014 California MUTCD
• Source: 2009 FHWA MUTCD
• Revised and approved by Caltrans in 2012
• Updated in November 2014
2014 California MUTCD
• Pedestrian Clearance interval
• Bicycle Minimum Green Time
• Minimum Yellow Change Interval
Pedestrian Clearance Interval
• WALK time (7 sec.)
• Pedestrian Clearance Time (3.5 ft/sec)
� Flashing DON’T WALK time
� Buffer time (3 seconds)
Pedestrian Clearance Time
• Ramp to Ramp (longest)
• Curb to Curb (shortest)
• Ramp to Curb extension (average)
Crossing distance
Crossing distances options
120 ft140 ft
ramp
curb
curb
ramp
120 ft108 ft
110 ft
116 ft
Curb to Curb
Pedestrian Crossing Distance
Ramp to ramp
140 ft123 ft
127 ft
127 ft
35 sec31 sec
32 sec
33 sec
Pedestrian Clearance Time
40 sec36 sec
37 sec
37 sec
Curb to Curb Ramp to ramp
Crossing speed = 3.5 ft/sec
Buffer Interval
28 sec24 sec
25 sec
26 sec
Flashing DON’T WALK
29 sec
30 sec
30 sec
Curb to Curb Ramp to ramp
5 sec 2 sec
33 sec
28 sec24 sec
25 sec
26 sec
Flashing DON’T WALK
Curb to Curb
5 sec 2 sec
40 sec36 sec
37 sec
37 sec
Ramp to ramp
Best case Worst case
Bicycle Minimum Green Time
140 ft
152 ft
155 ft
145 ft 140 ft
Bicycle Crossing distances
130 ft
127 ft
137 ft
Bicycle Minimum Green Time
10 sec
11 sec
11 sec
10 sec 9 sec
8 sec
8 sec
9 sec
Bicycle Minimum Green Time
• Video detection and /or bicycle loops
� Detects cars and bicycles
� Provide separate inputs into controller
• Radar detection
� Detects cars or bikes in the intersection
� Holds call until vehicle path is clear
Hardware solutions
Yellow Clearance
• The minimum yellow change interval for through traffic
movement shall be determined by using the 85th percentile
speed of free-flow traffic rounded up to the next 5 mph
increment.
• Where the posted or prima facie speed limit is higher than the
rounded value, use the posted or prima facie speed limit for
determination of the minimum yellow change interval for the
through traffic movement.
• See Table 4D-102(CA) sub-heading “a”.
2014 CA MUTCD
Yellow Clearance
• If the 85th percentile speed data is not available, the minimum
yellow change interval for through traffic movements shall be
determined by:
� adding 7 miles per hour to the posted or prima facie speed
limits of 30 mph or higher, and
� by adding 10 miles per hour to the posted or prima facie
speed limits of 25 mph or less.
• See Table 4D- 102(CA) sub-heading “b”.
2014 CA MUTCD
Minimum Yellow
2014 CA MUTCD
Speed85th Percentile is
available
Based on Posted
Speed (no 85th)
15 3.0 3.0
20 3.0 3.2
25 3.0 3.6
30 3.2 3.7
35 3.6 4.1
40 3.9 4.4
45 4.3 4.8
50 4.7 5.2
55 5.0 5.5
60 5.4 5.9
65 5.8 5.9
Other parameters that affect traffic
operations
• Vehicle extension
� extend green time
• Detector Lock
� Locks a call during yellow or red
� Detector call is released next green
Vehicle Extension
• Extension, Passage time = 5 sec
• 50 mph, Advance detector at 345 ft.
5 sec
4321043210 55
Vehicle Extension
• Extension = 2 sec
• Advance Loop extension = 3 sec
5 sec
2121010 32
Detector Lock
• Exploit some of MUTCD’s not clearly defined concepts,
such as the method to measure pedestrian crossing
distances – use the shortest distance;
• Understand MUTCD’s formulas and options, and always
reduce the timing parameters by using all available
options, such as reducing the Bicycle minimum green and
the Pedestrian Clearance, by subtracting both Yellow and
All-red intervals.
How to minimize MUTCD impact on
traffic signal operation?
• Use hardware solutions, such as video detection and radar-
based detection , to reduce minimum greens
• Fine-tune other timing parameters, such as Vehicle
Extension and Detector Lock, to further limit the amount of
wasted time during signal operation
How to minimize MUTCD impact on
traffic signal operation?
QUESTIONS