INVESTIGATION OF THE PLATT/ARABATLIAN CRASH
REPORT September 17, 2010
This two-vehicle angle collision occurred October 19, 2006, at about 9:12 p.m., in Westtown
Township, Chester County, Pa. The collision involved a 2006 Honda Accord four-door sedan,
operated by Kevork Arabatlian, and a 2001 Acura TL four-door sedan, operated by Laura Platt.
The collision occurred as Arabatlian was entering SR 352 (Chester Road) from Carmac Road.
Platt’s passengers were Alyssa Gallen and Georganna Amadio. Arabatlian’s passenger was
Zwart Arabatlian who was injured in the crash and subsequently died.
Plaintiff Arabatlian has claimed that the owners of 912 So. Chester Road property, Frank and
Dorothy Rogers, are responsible for the collision because
…the Rogers Property had shrubs, trees, and other landscaping improperly and negligently
situated and maintained so as to create an obstruction to the vision of motorists traveling
through the intersection of Carmac Road and Route 352 (Chester Road). (Complaint,
This investigation was performed to determine if shrubs or trees located on the Rogers property
created a sight obstruction which made the corner sight distance substandard in a manner that
was a cause of the collision.
2. AVAILABLE INFORMATION
1. Pennsylvania Police Crash Report, by Investigator Ptlm. David Leahy of the
Westtown/East Goshen Regional Police Department.
2. Photos of the two cars:
a. Three 8 x 6” color photos of the Acura.
b. One 8-1/2 x 11” black and white photo of the Honda with date
10/26/2006. (Exhibit 2 to Crupi deposition)
c. Four 8-1/2 x 11” black and white photos of the Acura with date
10/26/2006. (Exhibit 2 to Crupi deposition)
d. Sixteen 4 x 6” black and white photos of the Honda.
e. Six 4 x 6” black and white photos of the Acura.
a. Georgianna Amadio October 19, 2006
b. Kevork Arabatlian November 14, 2006
c. Mark Crupi, ear witness August 17, 2009.
d. Alyssa Gallen February 1, 2007.
e. Laura Platt November 7, 2006.
f. Laura Platt January 26, 2007.
4. Numerous photos of the collision site, taken subsequent to the collision. The
photos taken closest in time are dated 27/10/2006, eight days after the collision.
These are color digital photos: one each of the approach for both operators, and
two of the left corner view from Carmac Road.
5. Information provided by the plaintiff:
b. Report of Richard C. Moakes, CEng. August 31, 2010.
c. Response to Defendants Interrogatories and Request for Production of
d. Response to Supplemental Interrogatories from Rogers.
6. Information provided by Rogers:
a. Response to Plaintiff’s Interrogatories.
b. Response to Plaintiff’s Request for Production of Documents.
c. Request for Admissions to all Parties.
7. Information provided by Westtown Township:
a. Response to Plaintiff’s Interrogatories and Request for Production of
Documents, Sets I and II of both.
b. Response to Rogers Supplemental Interrogatories.
8. Information provided by the McCabes (adjacent property owners):
a. Response to Westtown Township Interrogatories and Request for
Production of Documents.
b. Response to Rogers Supplemental Interrogatories.
c. Response to Plaintiff’s Request for Production of Documents.
d. Response to Plaintiff’s Expert Interrogatories.
e. Response to Plaintiff’s Supplemental Interrogatories.
f. Response to Plaintiff’s Interrogatories, Set I.
9. Information provided by the Pennsylvania Department of Transportation
a. Response to Rogers Interrogatories, Set I.
b. Response to Rogers Supplemental Interrogatories.
c. Response to Plaintiff’s Interrogatories, Set I and II.
d. Response to Westtown Township’s Interrogatories.
e. Response to Westtown Township’s Request for Production of Documents.
f. Video Log of Route 352 northbound.
10. Information provided by the Platts.
a. Response to Westtown Township’s Interrogatories.
b. Response to Westtown Township’s Request for Production of Documents.
c. Supplemental answers to Westtown Township’s Interrogatories.
d. Supplemental answers to Plaintiff’s Interrogatories.
e. Response to Plaintiff’s Interrogatories.
f. Response to Plaintiff’s Expert Witness Interrogatories.
g. Response to Plaintiff’s Insurance Interrogatories.
h. Response to Plaintiff’s First Supplemental Interrogatories.
i. Response to Plaintiff’s Request for Production of Documents.
j. Response to Plaintiff’s First Supplemental Request for Production of
k. Response to Plaintiff’s Insurance and Expert Witness Interrogatories.
11. Deposition transcripts:
a. Kevork Arabatlian July 8, 2010
b. Lofti Arabatlian July 8, 2010
c. Ohannes Arabatlian August 5, 2010
d. Mania Arabatlian August 5, 2010
e. Georgeana Amadio August 5, 2010
f. Michael Conway, first responder August 5, 2010
g. Mark Crupi, August 5, 2010
h. Alyssa Gallen, March 12, 2010
i. Anne Jordan, ear witness August 5, 2010
j. Cpl. David Leahy August 5, 2010
k. Laura Platt March 12, 2010
12. My site inspections, measurements and photos of September 15, 2009 and July
3. DESCRIPTION OF THE COLLISION
Platt was driving south on Chester Road, and Arabatlian was entering Chester Road from
Carmac Road and turning left to go north on Chester Road, when the collision occurred.
The Police Crash Report states:
Unit #1 [Arabatlian] states he was turning left onto N. Chester Rd. from Carmac Rd.
Unit #2 [Platt] states that Unit #1 pulled out onto N. Chester Rd. all of the sudden as she
was about to pass Carmac Rd. and struck her. Unit #1 states that he was stopped at the
stop sign and let two cars heading southbound on N. Chester Rd. pass before entering
onto N. Chester Rd. Operator of unit #1 states that Unit #2 did not have its headlights on.
Operator of unit #2 states that her vehicles headlights were on. Witness #1 [Crupi], who
did not witness the accident but came out of his residence after hearing the crash, states
that when he went to Unit #2 to turn off the vehicles ignition he observed that the
headlights were not on. Unit #1 suffered severe front end damage. Unit #2 suffered
severe damage to the passenger side front fender and wheel area.
The crash occurred when it was dark (no street lights). It was raining and the roadway surface
was wet. (Police Report)
4. DESCRIPTION OF THE COLLISION SITE
The collision occurred at the intersection of Chester Road and Carmac Road. Adjacent land use
is residential. The terrain is rolling.
Chester Road is State Route 352, SR 0352, under the jurisdiction of the Pennsylvania
Department of Transportation (PaDOT). Chester Road is oriented north-south and is a two-lane,
two-way, 22.5-foot wide, rural collector. Chester Road is straight, at a 5 to 6% upgrade
southbound, and is normally crowned. The worn asphalt pavement is marked with solid double-
yellow centerlines and solid white edgelines. Outside the southbound edgeline, and for Platt’s
approach, there is a 3-foot wide asphalt shoulder, followed by a grassed slope with trees and
bushes. The speed limit is posted 40 mph1.
Carmac Road (T 487) is under the jurisdiction of Westtown Township. It is 19 feet wide; its
surface is worn asphalt. It slopes down to intersect SR 352 from the west. There is a Stop sign
located 18 feet from the SR 352 edge line, which controls right-of-way through the intersection.
The Police Report shows the speed limit on Chester Road as 45 mph. However, at my 2009 inspection, the speed
limit for southbound Chester Road was posted 40 mph, and PaDOT states, in Answers to Interrogatories, Set I, that
the speed limit at the time of the crash was 40 mph, and provided Traffic Sign Installation Order No. 2502, which
shows the road was signed for a 40 mph speed limit as of 10-28-05.
The two closest properties in the corner formed by Carmac Road and SR 352 to the north, in the
sight triangle for Arabatlian, are owned by John and Donna McCabe and Frank and Dorothy
Rogers. The McCabe property is closest to Carmac Road.
At the site, on 9/19/09, and under the same foliage conditions as those in 10/27/2006 photos, I
measured the daylight left corner sight distance to be 396 feet, with the eye 16 feet back from
edge of travel lane and 657 feet, with the eye 10 feet back from the edge of the travel lane. At 16
feet from the edge of the travel lane, the restriction to sight is due to branches of a tree on the
McCabe property, bushes on Rogers’ property and a mailbox with the number 912. At 10 feet
from the edge of the travel lane, the restriction to sight is due to a vertical curve in the profile of
the road. These conditions are shown in Photos 1 and 2.
Photo 1. View with eye at 3'-6 and 16 feet from travel lane in 2009.
Under nighttime visibility conditions, headlights would extend the 396 foot left corner sight by
200 feet. For the 2006 Honda, the driver would sit 8 feet back from the front of the car.
Therefore, the measured distances correspond to the front of the car being 2 and 8 feet from the
edge of the through traffic lane. Note that PaDOT defines2 the measuring point for available
corner sight distance as being with “…the driver’s eye 10 feet back from the near edge of the
PaDOT Publication 46, Traffic Engineering, 2008 edition. Page 11.1-1.
Photo 2. View with eye at 3'-6 and 10 feet from travel lane in 2009.
Under nighttime visibility conditions, headlights would not extend the 657 foot left corner sight
distance because the visibility restriction is due to a vertical curve in the roadway.
A 27/10/2006 corner view photo is shown in Photo 3. In this photo the mailbox can again be
Photo 3. Corner view taken close to time of collision.
Using features in the 27/10/2006 photo, on July 19, 2010 I determined that Photo 3 was taken
with the eye at a distance of 11 feet from the edge line. I located objects in this photo as follows:
Distance from Object
115 feet the white mailbox on the right side of the photo;
204 feet the first pole on the right side of the photo;
384 feet the second pole on the right side of the photo;
496 feet the yellow warning sign, in front of the third pole, on the right side
of the photo.
Based on the 27/10/2006 photo taken 8 days after the collision, I conclude that the sight
distances at my 2009 inspection were substantially the same as those at the time of the collision.
The damage to the vehicles is consistent with the front of Arabatlian’s Honda striking the right
front of Platt’s Acura. There is more buckling and damage on the right side of the Honda,
consistent with Arabatlian making a left turn and being at a slight angle to the Acura at impact.
Testimony indicates that the Acura went into the opposing lane as a result of the collision. Both
of the airbags in the 2006 Honda are deployed. These two factors are indicative of the Honda’s
forward speed at impact.
The Insurance Institute for Highway Safety explains3,
When do airbags deploy?
Airbags are designed to deploy only when they might be needed to prevent serious injury. In order for
airbags to be effective they must deploy early in a crash; in a frontal crash this typically occurs within the first
50 milliseconds (0.05 seconds). A vehicle's airbag control module relies on feedback from crash sensors to
predict whether an event is severe enough to warrant an airbag deployment.
Frontal airbags: Frontal airbags are designed to inflate in moderate to severe frontal crashes. Among
airbags with advanced features that include a safety belt sensor, there are different inflation thresholds
depending on whether people are using their safety belts. One threshold used by airbag designers is
"must deploy" which includes a situation such as an impact into a rigid wall of 10-12 mph for
unbelted occupants. The "must deploy" threshold is slightly higher — about 16 mph — for belted
occupants because the belts alone are likely to provide adequate protection up to these moderate
speeds. Frontal airbags may deploy to help protect occupants in side impacts if there is sufficient forward
deceleration during the crash. For example, if a vehicle is moving forward at the time of a side impact, frontal
airbags can help prevent serious injuries.
Advanced airbags compliant with government crash performance standards have been required in all
passenger vehicles since model year 2007. Advanced airbags are designed to suppress deployment or alter
deployment characteristics to reduce the risk of injury by the airbag if weight sensors in the seat detect that
a front-seat passenger is small or in a child safety seat. Advanced airbags also can deploy at a lower energy
level or pressure when passengers are small or out of position, or if the crash is of very low severity.
Assuming the Honda’s impact speed was the minimum for airbag deployment of 10 to 12 mph,
that Arabatlian accelerated at a normal rate4, and that Platt’s speed was less than or equal to 40
mph5, then the Acura was no further than 210 feet away when Arabatlian started to move. This
distance is well within the 400 feet of daylight sight distance available with the front of the car
8 feet from the edge of the through travel lane.
4.83 feet per second squared; per Topic 862—Drag Factor and Coefficient of Friction in Traffic Accident
Reconstruction. Traffic Accident Reconstruction, Fricke. Northwestern University Traffic Institute.
Platt’s statement and testimony are that her speed was 30, 35 mph.
If Arabatlian stopped with his eye 10’ from the travel lane, he would have accelerated 5 feet to
impact. Assuming Arabatlian traveled 5 feet, from a stop to impact, that Arabatlian accelerated
at a normal rate, and that Platt’s speed was less than or equal to 40 mph, then the Acura was no
further than 90 feet away when Arabatlian started to move.
If Arabatlian stopped with his eye 14.5’ from the travel lane, he would have accelerated 9.5 feet
to impact. Assuming Arabatlian traveled 9.5 feet, from a stop to impact, that Arabatlian
accelerated at a normal rate, and that Platt’s speed was less than or equal to 40 mph, then the
Acura was no further than 120 feet away when Arabatlian started to move.
Arabatlian’s view of the oncoming Platt car was not obstructed by vegetation at normal stopping
positions on Carmac Road.
5.2 Corner Sight Distance. Any intersection is hazardous because crossing traffic, moving
in different directions, is trying to occupy the same space. As such, traffic safety
countermeasures, such as positive assignment of right-of-way and adequate corner sight
distances, are required to control conflicts and provide drivers with sufficient view of other
vehicles and thus make the intersection reasonably safe.
Regarding sight distance at intersections, PaDOT states6:
F. Intersection Sight Distance. Since each intersection has the potential for several different types of
vehicle conflicts, those conflicts can be greatly reduced through provisions for proper sight distances and
appropriate traffic controls. The driver of a vehicle approaching an intersection should have an
unobstructed view of the entire intersection, including any traffic control devices, and sufficient lengths
along the intersecting highway to permit the driver to anticipate and avoid potential collisions.
Procedures to determine sight distances at intersections are presented below according to different types of
traffic control. For additional information concerning intersection sight distances, refer to the AASHTO
Green Book, Chapter 9.
2. Case B - Intersections with Stop Control on the Minor Road. Departure sight triangles for
intersections with stop control on the minor road should be considered for three situations:
Case B1 - Left turns from the minor road;
Case B2 - Right turns from the minor road; and
Case B3 - Crossing the major road from the minor road approach.
Intersection sight distance criteria for stop-controlled intersections are longer than stopping sight distance
to ensure that the intersection operates smoothly. Minor road vehicle operators can wait until they can
proceed safely without forcing a major-road vehicle to stop.
a. Case B1 - Left Turn from the Minor Road. Departure sight triangles for traffic approaching
from either the right of the left, should be provided for left turns from the minor road onto the major
PaDOT Publication 13M (DM-2), Design Manual, Part 2, Highway Design, Chapter 2. July 2002 edition.
road for all stop-controlled approaches. The length of the leg of the departure sight triangle along the
major road in both directions is the recommended intersection sight distance for Case B1.
The vertex (decision point) of the departure sight triangle on the minor road should be 4.4 m (14.4 ft)
from the edge of the major-road traveled way. This represents the typical position of the minor-road
driver's eye when a vehicle is stopped relatively close to the major road. Where practical, it is desirable
to increase the distance from the edge of the major-road traveled way to the vertex of the clear sight
triangle from 4.4 m to 5.4 m (14.4 ft to 17.8 ft). This increase allows 3.0 m (10 ft) from the edge of the
major-road traveled way to the front of the stopped vehicle, providing a larger sight triangle. The
length of the sight triangle along the minor road is the sum of the distance from the major road plus
one-half lane width for vehicles approaching from the left, or one and one-half lane widths for vehicles
approaching from the right.
The design values for intersection sight distance for passenger cars are shown in Table 2.12.
Table 2.12 shows, for a design speed of 45 mph7, the following
360 feet Stopping sight distance
500 feet Intersection sight distance.
The available left corner sight distance from Carmac Road was measured under daylight
conditions to be 396 feet, with the eye 16 feet from the edge of the through travel lane; the
restriction to visibility was due to due to branches of a tree on the McCabe property, bushes on
Rogers’ property and a mailbox with the number 912. At a distance of 14.5 feet from the edge of
the through travel lane, the available left corner sight distance would be greater and is estimated
to be 425 feet. Therefore the available sight distance exceeded the criteria for stopping sight
distance and was 75 feet short of the intersection sight distance criteria. Considering that the
collision occurred during nighttime visibility conditions and that headlights would extend the
corner sight distance 200 feet, the available sight distance also exceeded the criteria for
intersection sight distance.
Design speed is taken as 5 mph over the posted speed limit.
5.3 Arabatlian’s actions. At the crash scene, Arabatlian said that he let two cars heading
southbound pass before entering Chester Road, and that the Platt car didn’t have its headlights
on. Moakes examined photos of the damaged Acura, considered what both Arabatlian and Platt
said and the testimony of Crupi, as well as the mechanical/electrical characteristics of Platt’s car
and concluded “…that the headlights of the Acura TL were not on at the time of the collision
with the Honda Accord”. The Police Report stated there were no street lights, and the
investigating officer confirmed the absence of street lights at his deposition. It was either raining
or overcast8. Therefore without headlights Platt’s car would not be visible to Arabatlian.
As shown earlier, Arabatlian’s speed at impact was at least 10 to 12 mph. To achieve this speed
with normal acceleration, from an assumed stop, and impact Platt’s car at a distance of 3 feet
from the edgeline, Arabatlian had to have started with the front of his car more than 20 feet from
the edge line.
The 2004 Pennsylvania Driver’s Manual states,
The STOP sign is the only eight-sided or octagon-shaped sign you see on the highway.
At an intersection with a STOP sign, you MUST stop and wait for pedestrians and cross
traffic to clear the intersection before you go again. Slowing down without coming to a
full stop is illegal.
When you see a crosswalk or a stop line, stop before the front of your car reaches the
painted line. If you cannot see traffic, yield to any pedestrians, then carefully pull forward
past the line until you can see clearly. Stop, check for traffic and pedestrians, then go
ahead when the intersection is clear. (Page 10)
Arabatlian should have pulled forward to where he could see clearly down Chester Road.
As shown earlier, Arabatlian’s view of the oncoming Platt car was not obstructed by vegetation
at normal stopping positions on Carmac Road.
I conclude that this crash occurred either because Platt did not have her headlights on or because
Arabatlian started his move too far from Chester Road, or that Arabatlian simply failed to look
for oncoming traffic. There was nothing about the Rogers’ property that was a cause of this
Weather Underground data for 10/19/06.
Within the bounds of reasonable professional certainty, and subject to change if additional
information becomes available, it is our professional opinion that:
1. The daylight left corner sight distance from Carmac Road is 400 feet, with the front of
the car 8 feet back from edge of travel lane and 650 feet, with the front of the car 2 feet
back from the edge of the travel lane. At 8 feet from the edge of the travel lane, the
restriction to sight is due to branches of a tree on the McCabe property, bushes on
Rogers’ property and a mailbox No. 912. At 2 feet from the edge of the travel lane, the
restriction to sight is due to a vertical curve in the profile of the road.
2. Under nighttime visibility conditions, headlights would extend the above 400 foot left
corner sight by 200 feet to 600 feet.
3. Platt’s Acura was no further than 210 feet away when Arabatlian started to move. This
distance is well within the 400 feet of daylight sight distance available with the front of
the car 8 feet from the edge of pavement.
4. Arabatlian’s view of the oncoming Platt car was not obstructed by vegetation at normal
stopping positions on Carmac Road.
5. The daylight sight distance for Arabatlian exceeded the criteria for stopping sight
6. At night, the available sight distance also exceeded the criteria for intersection sight
7. This crash occurred either because Platt did not have her headlights on or because
Arabatlian started his move too far from Chester Road, or that Arabatlian simply failed to
look for oncoming traffic.
8. There was nothing about the Rogers’ property that was a cause of this collision.
Lance E. Robson, P.E.