Transcript
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Collision Review
Madison Street and Emerald Street
Riverside, California
May 13, 2012
• Presented by Officer Greg Matthews
– Collision Reconstruction Officer, 7 years
– Traffic Accident Investigator, 5 years
– Major Accident Investigation Team (MAIT), 13 years
– Police Officer, 18 years
– POST training includes Basic, Intermediate, and Advanced Collision
Investigation, Reconstruction, Vehicle vs Pedestrian Reconstruction,
Speed Determination from Crush Analysis, Field Evidence Technician
– Member of the Southwest Association of Technical Accident
Investigators and the California Association of Accident
Reconstruction Specialist
– Member of test‐staff at SATAI vehicle vs pedestrian crash tests, 17
staged collisions, Anaheim, California (2007)
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Party Summary
• Party #1: Michael Boulerice, 28 years
Riverside Police Officer, 5 years
Driver, 2009 Ford Crown Victoria
• Party #2: Isabel Pablo, 57 years
3 years in the United States
Deceased
Pedestrian
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Collision Summary
• Officer Boulerice was driving North on Madison St, towards Emerald St
at approximately 7:49am.
• His vehicle was traveling at 40 MPH.
• Ms. Pablo crossed into the street in front of Officer Boulerice’s vehicle
from the southeast corner of Madison and Emerald, outside of the
marked crosswalk. Because of visual impedements along the east side
of the street, Officer Boulerice could not see Pablo until she had walked
almost 20 feet into the street.
• Officer Boulerice was unable to stop his vehicle before it struck Pablo.
• Ms. Pablo died as a result of injuries sustained in the collision.
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Considerations
• According to Sergeant B Smith (RPD), Officer Boulerice told
him, “I didn’t even see her. I was looking down at my MDC.”
• A partially typed message (“mad /”) was on the MDC screen.
• The posted speed limit on Madison St is 35 MPH.
Phone/Text Messages
• A search warrant was served on Officer Boulerice’s
cell phone records.
• Warrant covered one‐hour before and one‐hour
after collision.
• No calls or texts sent or received before collision.
• Two calls were received and one made in the hour
after the collision.
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Witnesses
• #1 RG
– Stopped his vehicle S/B Madison to allow Pablo to cross the street.
– “Nodded” Pablo to start to cross.
– Saw police vehicle approaching, realized the officer did not see Pablo.
– Honked his vehicle’s horn in an attempt to warn Pablo.
– Looked away from the collision (did not see impact).
– Unable to estimate the vehicle’s speed or see the vehicle’s driver.
Witnesses
• #2 MD
– Walking on church property near northwest corner.
– Saw Pablo prior to collision, only noted her manner of clothing.
– Did not see the police car approaching.
– Saw Pablo come to rest in the street, but did NOT see the collision.
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Witnesses
• #3 Officer Neely Nakamura, Riverside Police Department
– Approximately 100 yards behind Officer Boulerice on Madison St.
– Estimated both vehicle’s speed at approximately 40 MPH.
– Saw Boulerice’s police car brake and swerve suddenly to the left.
– Heard collision but did not see it.
– Did not see Pablo until after exiting her vehicle.
Witnesses
Video: Officer Nakamura’s dash‐cam
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Witnesses
• Other people were contacted at the scene, but it was
determined that they didn’t actually see the collision, or only saw
the aftermath.
• Despite publishing a press release with a plea for further
witnesses, no other witnesses to the collision were found.
• Three witnesses were unaccounted for:
– Two women were standing at the southwest corner,
reportedly selling Tupperware to church‐goers.
– One man was sitting on the curb on the northeast corner.
• Several additional contacts were attempted in the area, but no
one admitted to seeing anything.
Speed Determination
This is a unique case.
Video in the police car…
…at the library
…at the public utilities building
Having the same car for testing
at the same location as the collision.
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Speed Determination
• Officer Boulerice’s police car was equipped with a video
recording system, called COBAN.
• An expert from an outside agency added a “1/1000
th
” of a
second time‐stamp to the video.
• Identification of known roadway features allowed an
accurate determination of the vehicle’s speed just prior to
impact.
Speed Determination
• Step 1 – A physical feature on the roadway was identified: a
spot where the asphalt has been repaired and re‐patched.
The exact time of the frame is recorded (00:16.083sec).
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Speed Determination
• Step 2 – A second physical feature on the roadway was identified:
the bottom of the “PED” intersects the top of the car’s push‐bar.
The exact time of the second frame is recorded (00:18.218sec).
Speed Determination
• The two roadway features are located at the scene and the
distance between the two measured.
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Speed Determination
• The amount of time it takes the car to travel from one
reference point to the next is calculated:
Ref time #2 18.218
Ref time #1 ‐ 16.083
Elapsed time 2.135 sec.
Speed Determination
Final Step ‐ Calculate the vehicle’s speed using the
“constant velocity” formula:
: =
J
t
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Speed Determination
Final Step ‐ Calculate the vehicle’s speed using the
“constant velocity” formula:
d = distance
: =
12S.S
t
: =
J
t
Speed Determination
Final Step ‐ Calculate the vehicle’s speed using the
“constant velocity” formula:
t = time
: =
12S.S
2.1SS
: =
12S.S
t
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Speed Determination
Final Step ‐ Calculate the vehicle’s speed using the
“constant velocity” formula:
: =
12S.S
2.1SS
: = S8.6 ¡cct pcr scconJ
or
4u milcs pcr bour
Speed Verification
• Officer Boulerice’s vehicle was equipped with a GPS device.
• The device “reports” the vehicle’s speed, location, and
heading to the Dispatch Center approximately every 1/10
th
of a mile.
• There is an accuracy of approximately +/‐2.27 miles per hour.
• The device recorded a speed of 41 miles per hour,
approximately 115 feet south of the impact area.
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Pedestrian Equations
• Equations based on studies of reported vehicle versus
pedestrian collisions.
• They provide an estimate of the vehicle’s speed at the
moment of impact.
• They usually provide a range of speeds and not an “exact”
answer.
• The formula is based on the distance from where the impact
occurred to the pedestrian’s resting place.
Searl – Minimum Speed
d
t
= Throw Distance f = coefficient of friction v = velocity
d
t
= 62.7 f = 0.66 (recommended by Searl)
:
mìn
=
2¡gJ
1 +¡
2
:
mìn
=
2 (u.66)(S2.2)(62.7)
1+.66
2
:
mìn
= 18S6.S672
:
mìn
= 4S.u8 ¡ps or 29. 37 mph
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Searl – Maximum Speed
d
t
= Throw Distance f = coefficient of friction v = velocity
d
t
= 62.7 f = 0.66 (recommended by Searl)
:
mux
= 2¡gJ
:
mux
= 2 .66 S2.2 62.7
:
mux
= 266S.uuu8
:
mux
= S1.62 ¡ps ur 35. 19 mph
Collins
d
t
= Throw Distance f = coefficient of friction v = velocity
d
t
= 62.7 f = 0.80 (recommended by Collins) h=2.8
o =
1
Su¡
=
1
Su (.8)
=
1
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= .u4166667
b =
b
2.7S
=
2.8
2.7S
=
1.67SS
2.7S
= .6129
c = -J
t
= -62.7
-b _ b
2
- 4oc
2o
-.6129 _ .6129
2
-(4)(.u4166667)(-62.7)
2 (.u4166667)
+ = 32. 1 MPH
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Slide to Stop
a = acceleration rate f = friction g = gravityd = distance
v
o
= original velocity v
f
= final velocity
f = 0.85 g = 32.2 fps
2
d = 18.53 v
o
= 58.66fps
-o = ¡g = .8S S2.2 = -27.S7¡ps
2
:
]
= :
o
2
+2oJ
S8.66
2
+(2)(-27.S7)(18.SS)
:
]
= 49.26 ¡ps or 33. 58 mph
Speed Verification
• Pedestrian impact calculations determined a speed between
29 and 35 miles per hour at impact.
• Slide‐to‐stop calculations, with pre‐braking speed of 40
miles per hour, determined the vehicle’s speed at impact to
be approximately 33 miles per hour.
• Pedestrian impact and slide‐to‐stop calculations verify
initial speed determination of 40 miles per hour.
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Driver’s Point of View
Landscaping and a parked vehicle made it impossible for Boulerice to see
Pablo until she walked at least 18 feet into the roadway.
Pedestrian Point of View
However, Pablo would have been able to clearly see the approaching police car when
she was 16 feet into the roadway, still 2.8 seconds and 11.4 feet away from impact.
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Visual Conspicuity
• An object’s visual conspicuity is a subjective
measurement of its ability to stand out to, or
attract the attention of, the viewer.
• An object is not conspicuous per se, it is only
conspicuous when it is sufficiently different from its
surroundings.
• We see objects, not because of their absolute
brightness, but by their contrast with the
background.
Visual Conspicuity
• Witness MD noted Pablo’s clothing as “typically
Guatemalan”: white and grey sweater, darker grey skirt.
Pablo’s traditional clothing provided low contrast to her visible background,
effectively camouflaging her, until she crossed in front of a white van.
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Visual Conspicuity
• Other factors within the vehicle also serve to reduce the visual conspicuity of
external items, as they distract the eye by providing more “noise” to the scene.
Perception & Reaction
• Perception and reaction time is that time period
during which a driver sees an object, identifies it as
a hazard, decides on how to react to the hazard,
and then physically reacts to the hazard.
• The ability of the driver to see something does not
mean that it has immediately been seen
(perceived) by the driver.
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Perception & Reaction
Perception
• Something becomes visible to the driver.
• The driver sees the item.
• The driver determines if the item is a threat.
Reaction
• The driver decides to do something.
• The driver does something.
Perception and Reaction
• P&R time of 1.5 seconds has been used in reconstruction in
past years. This time estimate goes back to the 1960’s or
earlier.
• Not realistic – studies were conducted under controlled
conditions with subjects who knew they were being tested.
• More recent studies have shown that 1.5 seconds is
unreasonable in urban environments and suggest “real‐
world urban driving” P&R times of 2.5 seconds or greater*.
* Society of Automotive Engineers technical paper #890732, “Perception and Reaction Time
Values for Accident Reconstruction” (Sens, M., Cheng, P., Wiechel, J., and Guenther, D.)
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Perception and Reaction
• Pablo first became visible to Boulerice when she walked out from behind the
landscaping and passed in front of a white van, providing sufficient contrast to
become conspicuous in comparison to the urban background (#1)
• Boulerice began braking approximately 1.69 seconds after Pablo
became visible (#2).
Photo 1 – First clearly visible Photo 2 – Vehicle begins braking
Perception and Reaction
• When a pedestrian enters the roadway, the
expectation is to see them walk from the sidewalk.
Visual impediments and Pablo’s low visual
conspicuity caused Boulerice not to perceive Pablo
until she was almost 20 feet into the street,
possibly explaining why she seemed to just appear
in the roadway in front of his car.
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Perception and Reaction
Even if Boulerice had been driving 35 MPH, he still would have been unable
to stop before colliding with Pablo.
Perception and Reaction
• At 40 MPH, Boulerice would have to perceive and react to
Pablo’s presence in 0.94 seconds or less in order to avoid
the collision.
• At 35 MPH, Boulerice would have to perceive and react
to Pablo’s presence in 1.3 seconds or less in order to
avoid the collision.
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Pablo Line of Sight
4 feet from the curb, 23.4’ to the AOI, the parked truck made it impossible for Pablo
or Boulerice to see the other’s approach. Pablo could only see 125 feet to the south,
while the police car was still 364 feet away.
Pablo Line of Sight
10 feet from the curb, 17.4’ to the AOI, the parked truck still made it impossible for
Pablo or Boulerice to see the other’s approach. Pablo could only see 179 feet to the
south, while the police car was still 275 feet away.
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Pablo Line of Sight
16 feet from the curb, 11.4’ to the AOI, visual impediments made it impossible for
Boulerice to see Pablo’s approach. However, Pablo could see over 700 feet to the
south, while the police car was only 186 feet away.
Pablo Line of Sight
18 feet from the curb, approximately 8’ to the AOI, Pablo became visible to
Boulerice. With approximately 2 seconds left to impact, Pablo could have easily
stopped and avoided the collision.
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The Crosswalk
• Large yellow signs serve to draw approaching motorists attention to the
marked crosswalk. The signs also serve to indicate to the pedestrian that
they should cross at the marked crosswalks.
The Crosswalk
• California Vehicle Code 275. "Crosswalk" is either: (a) That portion of a roadway included within the
prolongation or connection of the boundary lines of sidewalks at intersections where the intersecting
roadways meet at approximately right angles, except the prolongation of such lines from an alley across
a street.
• (b) Any portion of a roadway distinctly indicated for pedestrian crossing by lines or other markings on
the surface.
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The Crosswalk
Extension of the sidewalk west from the southeast corner of Madison and Emerald shows that
the path is interrupted by a concrete island planter.
The Crosswalk
If Pablo had crossed in the marked crosswalk, the collision
most likely would not have occurred.
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Conclusions
• Pablo crossed the street at a location that concealed her presence
until she was almost 20 feet into the roadway.
• Officer Boulerice’s perception of Pablo and reaction to her
presence were consistent with a normal person under similar
conditions.
• Officer Boulerice’s statement to Sergeant Smith that he did not
see Pablo was inconsistent with his reaction to her presence.
• None of the witnesses were able to estimate the police car’s
speed prior to impact.
• Officer Boulerice was driving 40 miles per hour.
• Officer Boulerice would not have been able to stop in time to
avoid Pablo even if he had been driving at the posted speed limit
of 35 MPH, instead of 40 MPH.
California Vehicle Code
21950. (a) The driver of a vehicle shall yield the right‐of‐way to a
pedestrian crossing the roadway within any marked crosswalk or within
any unmarked crosswalk at an intersection, except as otherwise provided
in this chapter.
(b) This section does not relieve a pedestrian from the duty of using due
care for his or her safety. No pedestrian may suddenly leave a curb or
other place of safety and walk or run into the path of a vehicle that is so
close as to constitute an immediate hazard. No pedestrian may
unnecessarily stop or delay traffic while in a marked or unmarked
crosswalk.
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California Vehicle Code
21954. (a) Every pedestrian upon a roadway at any point other than within
a marked crosswalk or within an unmarked crosswalk at an intersection
shall yield the right‐of‐way to all vehicles upon the roadway so near as to
constitute an immediate hazard.
(b) The provisions of this section shall not relieve the driver of a vehicle
from the duty to exercise due care for the safety of any pedestrian upon a
roadway.
Pedestrian Collision Stats
23 Fatal Pedestrian Collisions since 2007
• 15 (65%) Pedestrian at Fault collisions
• 5 (22%) Driver at Fault collisions
No prosecution brought against the driver
• 3 (13%) Driver at Fault collisions (Charges)
2 Felony DUI with Hit and Run
1 Misdemeanor vehicular manslaughter
77% of fatal pedestrian collisions do not result in
prosecution against the driver.
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