a report to for: george massey tunnel replacement project · a report to for: george massey tunnel...

A Report to

For:

GEORGE MASSEY TUNNEL REPLACEMENT PROJECT COLLISION DATA ANALYSIS

Submitted By:

SW1223

August 2015

GEORGE MASSEY REPLACEMENT PROJECT COLLISION DATA ANALYSIS - DRAFT

SW1223 – August 2015 1

1. INTRODUCTION

As part of the George Massey Tunnel Replacement Project, the Ministry of

Transportation and Infrastructure (the Ministry) requested a collision data analysis of

the Highway 99 corridor from the US Border to the Oak Street Bridge. Specifically, the

following tasks were requested as part of the study:

• Calculate average existing collision rates on the segmented study corridor; and

• Determine collision trends and patterns.

The purpose of this document is to outline the methodologies and assumptions used in

the analysis, and present the findings.

2. DATA SOURCES

There are two sources of collision data in British Columbia, and both were obtained as

part of this study:

• The Ministry’s Collision Information System (CIS), and

• Insurance Corporation of British Columbia (ICBC) Claims Data.

The CIS database of collisions is based on motor vehicle accident reports that are

generated by police-attended collisions. As such, the database underreports the actual

number of collisions because not all collisions are police-attended. All collisions are

geocoded using the Ministry’s Landmark Kilometre Inventory (LKI), which identifies

collision locations to the nearest 100 m. Collision configuration is provided in the

dataset. Collisions are also classified by severity – property damage only, injury and

fatality.

The ICBC claims data is as the name suggests, data from insurance claims after a

collision has occurred. ICBC claims data typically produces the most complete dataset.

Collisions are geocoded by latitude and longitude to the nearest landmark. Collision

configuration and severity is provided in the dataset. Unlike the CIS dataset, collisions

are classified as either property damage only or casualty, the latter of which is a

combination of injuries and fatalities.

Data from 2008 – 2012 was obtained for both datasets.


SW1223 – August 2015 2

3. AVERAGE COLLISION RATES

The Ministry publishes provincial average collision rates every four years on their

Highway Planning website. These average collision rates are calculated using data

from the CIS database. Thus, all average collision rate calculations presented in this

study were based on the CIS data.

Generally speaking, the average collision rate of a highway segment is calculated by

using Formula 1:

Formula 1

# # 365 1,000,000

The average collision rate is measured in units of collisions per million vehicle

kilometres (c/mvk), and provides a measure of the frequency of collisions in the study

segment.

3.1 Provincial Average Collision Rate

Most of the Highway 99 corridor would be classified under the “urban-freeway-divided-

4 lane+” (UFD4) highway classification. According to the Ministry Average Provincial

Collision Rates, UFD4 facilities have a collision rate of 0.30 c/mvk. This rate was

calculated using the tools and methodology embedded within the CIS. While Formula 1

was still used as the basis of these calculations, the system uses historic AADT volumes

and projections, examines the highway by incremental segments, and aggregates the

results. It should be noted that this average is calculated using the following highway

segments:

• Highway 1 from Horseshoe Bay to 160 Street;

• Highway 91 from Nordel Way to Highway 99;

• Highway 99 from Bridgeport Road to the northern end of the Oak Street Bridge;

and

• Highway 91A from Nordel Way to the northern end of Queensborough Bridge.


SW1223 – August 2015 3

3.2 Average Collision Rate – Highway 99

The tools embedded in the CIS were not used to calculate average collision rates on

Highway 99. It was desired to simplify the methodology and make it easier to replicate

for future analysis. The study corridor was segmented and a separate collision rate

was calculated for each segment and direction.

The Highway 99 corridor was divided into four segments:

1. US Border to Serpentine River;

2. Serpentine River to Highway 17A;

3. Highway 17A to Steveston Highway; and

4. Steveston Highway to Oak Street Bridge.

Exhibit 1 shows the location of the collisions on Highway 99, colour coded by the

segments described above.

Each segment contains at least one permanent count station to provide AADT statistics

and the traffic patterns within each segment are quite similar. Therefore, it would be

reasonable to calculate a collision rate for each individual segment. The estimated

collision rates for each Highway 99 segment are summarized in Figure 1 below.

Direction Segment Description Highway 99 Segments

1 2 3 4

NB/SB # of Collisions (CIS) 165 177 346 214

C/MVK 0.16 0.13 0.44 0.21

NB # of Collisions (CIS) 61 77 237 121

C/MVK 0.12 0.11 0.60 0.24

SB # of Collisions (CIS) 104 100 109 93

C/MVK 0.21 0.14 0.28 0.18

Figure 1 – Average Collision Rates on Highway 99 (2008-2012)

As seen in Exhibit 1, Segment 3 represents the Tunnel and the adjacent interchanges

at Steveston Highway and Highway 17A. Figure 1 shows that the collision rate on

Segment 3 is 0.44 c/mvk. This is significantly higher than the provincial average of 0.30

c/mvk for UFD4 facilities.

Sources: Esri, HERE, DeLorme, USGS, Intermap, increment P Corp., NRCAN, Esri Japan, METI, Esri China (Hong Kong), Esri (Thailand), TomTom, MapmyIndia,© OpenStreetMap contributors, and the GIS User Community

Exhibit 1 - Collision Locations

LegendSegment 1Segment 2Segment 3Segment 4


SW1223 – August 2015 4

4. ICBC CLAIMS DATA

Collision data was provided by ICBC. Collision data for intersections adjacent to

Highway 99 and nearby routes was collected. The data covered the period from 2008

to 2012. Data for 2013 was not included as not all insurance claims would have been

processed at the time of the analysis (January/February 2014). In total, 6,024 claims

were processed in the study corridor between 2008 and 2012.

4.1 Collision Locations

The location of these collisions were geocoded by ICBC to the nearest intersection or

landmark. As such, the ICBC geocoding is less granular compared to the Ministry CIS

dataset. Exhibit 2 shows the collisions that occurred on Highway 99 and intersections

adjacent to the corridor.

On the Highway 99 corridor itself, collisions appear concentrated around both north and

south approaches to the tunnel and the Steveston Highway and Highway 17A

interchanges. It should be stressed again that the ICBC data is geocoded to the nearest

landmark or intersection, and thus may not represent the actual location of the vehicle

collision. As such, collisions will be clustered around major intersections and

interchanges. However, the significant clustering of collisions around the Highway 17A

interchange and the Steveston Highway interchange indicate that collisions occur more

frequently in the general vicinity of the tunnel compared to other locations on

Highway 99.

Sources: Esri, HERE, DeLorme, USGS, Intermap, increment P Corp., NRCAN, Esri Japan, METI, Esri China (Hong Kong), Esri (Thailand), TomTom, MapmyIndia,© OpenStreetMap contributors, and the GIS User Community

Exhibit 2 - ICBC Claims Data Collision Frequency - Highway 99 Corridor (2008-2012)

Total Collisions1 - 100

101 - 200

201 - 300

301 - 400

401 - 500

500+


SW1223 – August 2015 5

4.2 Highway 99 Collision Trends

This section focuses on the 6024 collisions that occurred on Highway 99 or possibly

due to traffic conditions on Highway 99.

Figure 2 shows the collision frequency on Highway 99 by year and severity.

Figure 2 – Collision Frequency by Year

Generally, collision frequency has increased on an annual basis since 2009. Collision

severity has remained relatively constant in the past five years, ranging between 33%

and 39% casualties. It should be noted again that the ICBC database classifies collision

severity using two categories only – property damage only and casualties. Casualties

include collisions that cause injuries and fatalities.

Figure 3 shows the collision frequency on Highway 99 and adjacent intersections by

month and severity.


SW1223 – August 2015 6

Figure 3 – Collision Frequency by Month

Collisions occurred more frequently in mid-Spring (April and May) and late-Fall (October

and November). January and February experienced the fewest collisions. Collision

severity ranges from 32% casualties in December to 40% casualties in March.

Figure 4 shows the collision frequency on Highway 99 and adjacent intersections by

day of week and severity.

Figure 4 – Collision Frequency by Day of Week


SW1223 – August 2015 7

Collision frequency appeared fairly consistent between Tuesday and Fridays. Far fewer

collisions occurred on the weekends, likely due to reduced traffic volumes. Fewer

collisions occur on Monday compared to the other weekdays. This may be due to a

combination of the prevalence of statutory holidays on Monday, and human behavior.

Collision severity does not vary significantly between each day of the week.

Figure 5 and Figure 6 show the collision frequency on Highway 99 and adjacent

intersections by time of day and severity.

Figure 5 – Collision Frequency by Time of Day


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Figure 6 – Collision Frequency Percentages by Time of Day

Collisions occurred most frequently in the PM peak period, with 31% of all collisions

occurring between 3 and 6 pm. Collisions occurring between 12pm and 6pm accounted

for almost 50% of all collisions. Collision severity was fairly consistent between each

period, with the exception of the early morning. However, this discrepancy is most likely

because few collisions occur during those hours.

Figure 7 and Figure 8 show the collision frequency on Highway 99 by collision

configuration.


SW1223 – August 2015 9

Figure 7 – Collision Frequency by Collision Configuration

Figure 8 – Collision Frequency by Collision Configuration and Severity

The majority of the collisions that occurred on Highway 99 and adjacent intersections

are classified as rear-ends. Collision frequency of the four most common collision

configurations are shown in Figure 8. About 45% of all rear end collisions resulted in


SW1223 – August 2015 10

casualties. Other collision configurations generally resulted in a lower percentage of

casualties.

Figure 9 shows the overall severity of collisions on Highway 99 and adjacent

intersections.

Figure 9 – Collision Severity

The majority (63%) of the collisions that occurred on Highway 99 and adjacent

intersections resulted in “property-damage-only” collisions.

4.2.1 Top Ten Collision Locations on Highway 99 and

Adjacent Intersections

The top ten locations for vehicle collisions are shown in Table 3 below. As shown in

Figure 10, these ten locations represent 59% of all collisions on the Highway 99 corridor

and adjacent intersections. Collision trends at these ten locations are presented in this

section.


SW1223 – August 2015 11

Table 3 – Top Ten Collision Locations on Highway 99 and Adjacent

Intersections

Location Number of Collisions

Highway 99 at Steveston Highway Interchange 625

Steveston Highway at No. 5 Road 545

Highway 99 at Highway 17A Interchange 491

No. 5 Road at Westminster Highway 352

152 Street at 32 Avenue 321

George Massey Tunnel Mid Span 278

Highway 10 at Highway 99 Interchange 257

Highway 99 at King George Boulevard Interchange 252

Bridgeport Road On-ramp to Highway 99 NB 221

Highway 99 SB Off-ramp to Ladner 215

Figure 10 – Top Ten Collision Locations

Highway 99 at Steveston Highway Interchange

10%

Steveston Highway at No. 5 Road9%

Highway 99 at Highway 17A Interchange

8%

No. 5 Road at Westminster Highway

6%

152 Street at 32 Avenue5%

George Massey Tunnel Mid Span

5%

Highway 10 at Highway 99 Interchange

4%

Highway 99 at King George Boulevard Interchange

4%

Bridgeport Road On-ramp to Highway 99 NB

4%

Highway 99 SB Off-ramp to Ladner

4%

Other Locations41%

Top Ten Collision Locations on Highway 99 and Adjacent Intersections


SW1223 – August 2015 12

4.2.1.1 Highway 99 at Steveston Highway Interchange

Figure 11 shows the collision frequency at the Highway 99/Steveston Highway

interchange by year and severity.


Collision frequency has fluctuated between 100 and 140 per year while collision severity

decreased from a high of 41% casualties in 2010 to 25% in 2012. It should be noted

that improvements to the NB exit ramp were completed in late 2013 which is beyond

the period for which this data was analyzed (2008-2012). Therefore all accidents

included in this analysis took place prior to the implementation of this improvement.

Figure 12 shows the collision frequency at Highway 99/Steveston Highway interchange

by month and severity.



SW1223 – August 2015 13

Collisions occurred more frequently in the Spring months (April to June) and spiked

noticeably in August and November. The Winter months, January to March

experienced the fewest collisions. Collision severity ranged from 19% casualties in

February to 46% casualties in March.

Figure 13 shows the collision frequency at the Highway 99/Steveston Highway

interchange by day of week and severity.


Collision frequency appeared fairly consistent between Tuesday and Thursday. Far

fewer collisions occurred on the weekends, likely due to reduced traffic volumes. Fewer



Collisions occurred most frequently on Fridays. Collision severity varied between 28%

casualties on Mondays to 38% casualties on Thursdays.

Figure 14 and Figure 15 show the collision frequency at the

Highway 99/Steveston Highway interchange by time of day and severity.


SW1223 – August 2015 14




SW1223 – August 2015 15


occurring between 3pm and 6pm. Collisions occurring between 12pm and 6pm

accounted for 47% of all collisions. Collision severity varied between 28% casualties in

the 12pm to 3pm period, and 39% casualties in the 9am to 12pm period. Few collisions

occurred between 12am to 6am.


Highway 99/Steveston Highway interchange by collision configuration.



SW1223 – August 2015 16


The majority of the collisions that occurred at the Highway 99/Steveston Highway

interchange are classified as rear-ends (62%). Collision frequency of the four most

common collision configurations are shown in Figure 17. About 43% of all rear end

collisions resulted in casualties. Other collision configurations generally resulted in a

lower percentage of casualties.

Figure 18 shows the overall severity of collisions at the Highway 99/Steveston Highway

interchange.


SW1223 – August 2015 17


The majority (67%) of the collisions that occurred at the Highway 99/Steveston Highway

interchange resulted in “property-damage-only” collisions.


SW1223 – August 2015 18

4.2.1.2 Steveston Highway at No. 5 Road

Figure 19 shows the collision frequency at the Steveston Highway/No. 5 Road

intersection by year and severity.


Collision frequency has increased on an annual basis since 2009 while collision severity

decreased from a high of 34% casualties in 2008 to 17% in 2012.


intersection by month and severity.



SW1223 – August 2015 19

Collisions occurred more frequently in the Spring (April and May) and Summer (July

and August). Collision severity ranged from 13% casualties in April to 36 % casualties

in March and July.


intersection by day of week and severity.


Collision frequency appeared fairly consistent between Tuesday and Thursday. Fewer




Collisions occurred most frequently on Fridays. Collision severity varied between 22%

casualties on Fridays to 39% casualties on Mondays.

Figure 22 and Figure 23 show the collision frequency at the Steveston Highway/No. 5

Road intersection by time of day and severity.


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SW1223 – August 2015 21


occurring between 3 and 6 pm. Collisions occurring between 12 pm and 6 pm


the 12 pm to 3 pm period, and 38% casualties in the 6 am to 9 am period. Few collisions

occurred between 12 am to 6 am.

Figure 24 and Figure 25 show the collision frequency at the Steveston Highway/No. 5

Road intersection by collision configuration.



SW1223 – August 2015 22


The majority of the collisions that occurred at the Highway 99/No.5 Road intersection

are classified as rear-ends (55%). Collision frequency of the four most common

collision configurations are shown in Figure 25. About 38% of all rear end collisions

resulted in casualties. Other collision configurations generally resulted in a lower

percentage of casualties.

Figure 26 shows the overall severity of collisions at the Steveston Highway/No. 5 Road

intersection.


SW1223 – August 2015 23


The majority (72%) of the collisions that occurred at the Steveston Highway/No. 5 Road

intersection resulted in “property-damage-only” collisions


SW1223 – August 2015 24

4.2.1.3 Highway 99 at Highway 17A Interchange

Figure 27 shows the collision frequency at the Highway 99/Highway 17A interchange

by year and severity.


Generally, collision frequency has varied between 80 and 100 per year. Collision

severity has decreased from a high of 37% casualties in 2009 to 24% in 2012.





SW1223 – August 2015 25

Collisions occurred more frequently in the latter half of the year (June to December)

and January. Collision severity ranged from 24% casualties in June, July and

December to 50% casualties in September.


by day of week and severity.


Collision frequency appeared fairly consistent between Tuesday and Friday. Far fewer




Collisions occurred most frequently on Tuesdays, Thursdays, and Fridays. Collision

severity varied between 19% casualties on Saturdays to 38% casualties on Thursdays.

Figure 30 and Figure 31 show the collision frequency at the Highway 99/Highway 17A

interchange by time of day and severity.


SW1223 – August 2015 26




SW1223 – August 2015 27


occurring between 3 and 6 pm. Collision severity varied between 26% casualties in the

12 pm to 3 pm period, and 38% casualties in the 6 am to 9 am period. Few collisions


Figure 32 and Figure 33 show the collision frequency at the Highway 99/Highway 17A

interchange by collision configuration.



SW1223 – August 2015 28


The majority of the collisions that occurred at the Highway 99/Steveston Highway



collisions resulted in casualties. Other collision configurations generally resulted in a

lower percentage of casualties.

Figure 34 shows the overall severity of collisions at the

Highway 99/Highway 17A interchange.


SW1223 – August 2015 29


The majority (68%) of the collisions that occurred at the

Highway 99/Highway 17A interchange resulted in “property-damage-only” collisions


SW1223 – August 2015 30

4.2.1.4 No. 5 Road at Westminster Highway

Figure 35 shows the collision frequency at the No. 5 Road/Westminster Highway

intersection by year and severity.


Collision frequency has increased on an annual basis since 2010 while collision severity

varied from a high of 55% casualties in 2009 to 40% in 2008.

Figure 36 shows the collision frequency at the No. 5 Road/Westminster Highway

intersection by month and severity.


Collisions frequency is fairly constant throughout every month of the year, though an

anomaly is observed in December. Further analysis showed that a significant number


SW1223 – August 2015 31

of collisions occurred during December of 2008. Patterns are fairly consistent if that

month is removed from the dataset. Collision severity ranged from 32% casualties in

August to 50% casualties in May.

Figure 37 shows the collision frequency at the No.5 Road/Westminster Highway

intersection by day of week and severity.


Collision frequency appeared fairly consistent between Tuesday and Thursday. Fewer

collisions occurred on Sundays, Mondays and Fridays – collisions occurred more

frequently on Saturday compared to those days of the week. Collision severity varied

between 24% casualties on Fridays to 47% casualties on Wednesdays.


No. 5 Road/Westminster Highway intersection by time of day and severity.


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SW1223 – August 2015 33


occurring between 3 pm and 6 pm. Collisions occurring between 12pm and 6pm


the 6 pm to 9 pm period, and 50% casualties in the 9 pm to 12 am period. Few collisions



No. 5 Road/Westminster Highway intersection by collision configuration.



SW1223 – August 2015 34


The majority of the collisions that occurred at the No.5 Road/Westminster Highway

intersection are classified as rear-ends (66%). Collision frequency of the four most


collisions resulted in casualties, and 55% of all right angle collisions resulted in


casualties.


No. 5 Road/Westminster Highway intersection.


SW1223 – August 2015 35


The majority (60%) of the collisions that occurred at the

No. 5 Road/Westminster Highway intersection resulted in “property-damage-only”

collisions


SW1223 – August 2015 36

4.2.1.5 152 Street at 32 Avenue

Figure 43 shows the collision frequency at the 152 Street/32 Avenue intersection by

year and severity.


Collision frequency has increased considerably on an annual basis since 2008 while

collision severity varied from a low of 25% casualties in 2009 to a high of 42% casualties

in 2008.


month and severity.



SW1223 – August 2015 37

Collisions frequency was noticeably lower in the Summer months and September.

Collisions occurred more frequently between October and December. Collision severity

varied considerably between months, ranging from 17% casualties in April and 52%

casualties in February.




Collision frequency appeared fairly consistent between Monday and Friday. Far fewer

collisions occurred on the weekends, likely due to reduced traffic volumes. Collision

severity varied between 23% casualties on Saturdays to 49% casualties on Thursdays.

Figure 46 and Figure 47 show the collision frequency at the 152 Street/32 Avenue

intersection by time of day and severity.


SW1223 – August 2015 38




SW1223 – August 2015 39


occurring between 3 pm and 6 pm. Collisions occurring between 12pm and 6pm


the 9 am to 12 pm period, and 44% casualties in the 6 pm to 9 pm period. Few collisions


Figure 48 and Figure 49 show the collision frequency at the 152 Street/32 Avenue

intersection by collision configuration.



SW1223 – August 2015 40


The majority of the collisions that occurred at the 152 Street/32 Avenue intersection are

classified as rear-ends (66%). Collision frequency of the four most common collision



casualties.

Figure 50 shows the overall severity of collisions at the 152 Street/32 Avenue

intersection.


SW1223 – August 2015 41


The majority (64%) of the collisions that occurred at the 152 Street/32 Avenue

intersection resulted in “property-damage-only” collisions


SW1223 – August 2015 42

4.2.1.6 George Massey Tunnel Mid Span

Figure 51 shows the collision frequency at the George Massey Tunnel Mid Span by

year and severity.


Collision frequency has increased considerably on an annual basis since 2009 while

collision severity varied from a low of 43% casualties in 2010 to a high of 58% casualties

in 2011.


month and severity.



SW1223 – August 2015 43

Collision frequency was noticeably higher during the spring and early summer months

between March and June. Collision severity varied considerably between months,

ranging from a low of 29% casualties in November to a high of 71% casualties in April.




The highest collision frequency occurs during the weekdays, in particular Tuesday to

Friday. Far fewer collisions occurred on the weekends, likely due to reduced traffic

volumes. Collision severity is relatively consistent during the week at approximately

50% casualties with the exception of Saturdays.

Figure 54 and Figure 55 show the collision frequency at the George Massey Tunnel

Mid Span by time of day and severity.


SW1223 – August 2015 44




SW1223 – August 2015 45

Collisions occurred most frequency during the AM and PM peak periods, with 29% of

all collisions occurring between 6 am and 9 am, and 40% of all collisions occurring

between 3 pm and 6 pm. Collision severity is approximately 50% casualties during the

busiest times of the day (6 am to 6 pm). Few collisions occurred between 12 am to 6

am.

Figure 56 and Figure 57 show the collision frequency at the George Massey Tunnel

Mid Span by collision configuration.



SW1223 – August 2015 46


The majority of the collisions that occurred at the George Massey Tunnel Mid Span are

classified as rear-ends (86%). Collision frequency of the four most common collision


casualties.

Figure 58 shows the overall severity of collisions at the George Massey Tunnel Mid

Span intersection.


SW1223 – August 2015 47


Approximately half of the collisions that occurred at the George Massey Tunnel Mid

Span resulted in “property-damage-only” collisions and half resulted in casualties.


SW1223 – August 2015 48

4.2.1.7 Highway 10 at Highway 99 Interchange

Figure 59 shows the collision frequency at the Highway 10/Highway 99 interchange by

year and severity.


Collision frequency generally varies between 50 to 60 collisions per year, with 2010

being an exception to the trend. Collision severity increased from a low of 33%

casualties in 2008 to a high of 49% casualties in 2012.

Figure 60 shows the collision frequency at the Highway 10/Highway 99 interchange by

month and severity.



SW1223 – August 2015 49

Collision frequency showed fluctuations with fewer collisions occurring in March, June,

August, and November. Collisions frequency was highest in September. Collision

severity varied considerably between months, ranging from 17% casualties in

December to 60% casualties in June.

Figure 61 shows the collision frequency at the Highway 10/Highway 99 Interchange by



Collision frequency was highest during the weekdays. Far fewer collisions occurred on

the weekends, likely due to reduced traffic volumes. Collision severity varied between

24% casualties on Sundays to 63% casualties on Thursdays.

Figure 62 and Figure 63 show the collision frequency at the Highway 10/Highway 99

interchange by time of day and severity.


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all collisions occurring between 6 am and 9 am, and 32% of all collisions occurring

between 3 pm and 6 pm. Collision severity varied from 24% casualties between 12 pm

to 3 pm, to 51% casualties between 6 am to 9 am. Few collisions occurred between 12

am to 6 am.

Figure 64 and Figure 65 show the collision frequency at the Highway 10/Highway 99

interchange by collision configuration.



SW1223 – August 2015 52


The majority of the collisions that occurred at the Highway 10/Highway 99 interchange

are classified as rear-ends (57%). Collision frequency of the four most common

collision configurations are shown in Figure 65. About 55% of all rear end collisions



Figure 66 shows the overall severity of collisions at the Highway 10/Highway 99

interchange.


SW1223 – August 2015 53


The majority (61%) of the collisions that occurred at the Highway 10/Highway 99

interchange resulted in “property-damage-only” collisions.


SW1223 – August 2015 54

4.2.1.8 Highway 99 at King George Boulevard Interchange

Figure 67 shows the collision frequency at the Highway 99/King George Boulevard

interchange by year and severity.


Collision frequency remained consistent at approximately 40 collisions per year from

2008 to 2010 but increased considerably in 2011 and 2012. Collision severity ranged

from a low of 39% casualties in 2012 to a high of 53% casualties in 2011.


interchange by month and severity.



SW1223 – August 2015 55

Collision frequency was highest in April and during the fall and early winter months from

September to December. The lowest collision frequency months are January, March

and June. Collision severity varied between months, ranging from a low of 27% in

September to 71% in August.


interchange by day of week and severity.


Collision frequency was fairly consistent with the exception of Thursdays which showed

lower than average collision frequencies. Collision severity varied between 33%

casualties on Thursday to 60% casualties on Wednesdays.


Highway 99/King George Boulevard interchange by time of day and severity.


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SW1223 – August 2015 57


all collisions occurring between 6 am to 9 am, and 30% of all collisions occurring

between 3 pm to 6 pm. Collision severity varied from 35% casualties between 9 am

to 12 pm, to 57% casualties between 6 pm to 9 pm. Few collisions occurred between

12 am to 6 am.


Highway 99/King George Boulevard interchange by collision configuration.



SW1223 – August 2015 58


The majority of the collisions that occurred at the Highway 99/King George Boulevard


common collision configurations are shown in Figure 73. Approximately 62% of all rear

end collisions resulted in casualties. Other collision configurations generally resulted in

a lower percentage of casualties.


Highway 99/King George Boulevard interchange.


SW1223 – August 2015 59


A slight majority (54%) of the collisions that occurred at the

Highway 99/King George Boulevard interchange resulted in “property-damage-only”

collisions.


SW1223 – August 2015 60

4.2.1.9 Bridgeport Road On-ramp to Highway 99 NB

Figure 75 shows the collision frequency at the Bridgeport Road On-ramp to Highway 99

NB by year and severity.


Collision frequency remained consistent at approximately 40 to 50 collisions per year

from 2008 to 2009 but decreased in 2012. Collision severity ranged from a low of 27%

casualties in 2009 to a high of 42% casualties in 2011.


NB by month and severity.



SW1223 – August 2015 61

Collision frequency was highest during March, June and the fall and early winter months

from September to December. The lowest collision frequency months generally

occurred during the summer. Collision severity varied between months, ranging from

a low of 17% casualties in February to a high of 63% casualties in January.


NB by day of week and severity.


Collision frequency was generally higher during the weekdays compared to the

weekends. This is likely due to the presence of more vehicles on the road during the

weekdays. Collision severity varied between 23% casualties on Mondays to 42%

casualties on Sundays.

Figure 78 and Figure 79 show the collision frequency at the Bridgeport Road On-

ramp to Highway 99 NB by time of day and severity.


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SW1223 – August 2015 63

Collisions occurred with consistent frequency throughout the day. Collision severity

varied from 24% casualties between 12 pm to 3 pm, to 55% casualties between 9 pm

to 12 am. Few collisions occurred between 12 am to 6 am.

Figure 80 and Figure 81 show the collision frequency at the Bridgeport Road On-

ramp to Highway 99 NB by collision configuration.



SW1223 – August 2015 64


Approximately 48% of the collisions that occurred at the Bridgeport Road On-ramp to

Highway 99 NB are classified as rear-ends. Collision frequency of the four most

common collision configurations are shown in Figure 81. Approximately 42% of all rear

end collisions resulted in casualties. Other collision configurations generally resulted in

a lower percentage of casualties.

Figure 82 shows the overall severity of collisions at the Bridgeport Road On-ramp to

Highway 99 NB.


SW1223 – August 2015 65


The majority (66%) of the collisions that occurred at the Bridgeport Road On-ramp to

Highway 99 NB resulted in “property-damage-only” collisions.


SW1223 – August 2015 66

4.2.1.10 Highway 99 SB Off-ramp to Ladner

Figure 83 shows the collision frequency near the Highway 99 SB Off-ramp to Ladner

by year and severity.


Collision frequency has increased since 2008, hitting a plateau in 2010 of approximately

50 collision per year. Collision severity ranged from a low of 23% in 2008 to a high of

54% in 2011.

Figure 84 shows the collision frequency near the Highway 99 SB Off-ramp to Ladner




SW1223 – August 2015 67

Collision frequency was highest during the summer months from June to August. The

lowest collision frequency months occurred during the winter. Collision severity varied

between months, ranging from a low of 29% casualties in August to a high of 65%

casualties in May.

Figure 85 shows the collision frequency at the Highway 99 SB Off-ramp to Ladner by



Collision frequency was significantly higher during the weekdays compared to the

weekends. This is likely due to the presence of more vehicles on the road during the

weekdays. Collision severity varied between 33% casualties on Fridays to 60%

casualties on Saturdays.

Figure 86 and Figure 87 show the collision frequency near the Highway 99 SB Off-

ramp to Ladner by time of day and severity.


SW1223 – August 2015 68




all collisions occurring between 6 and 9 am, and 36% of all collisions occurring between


SW1223 – August 2015 69

3 and 6 pm. Collision severity varied from 25% casualties between 6 pm to 9 pm, to

45% casualties between 6 am to 9 am. Few collisions occurred between 9 pm to 6 am.

Figure 88 and Figure 89 show the collision frequency at the Highway 99 SB Off-ramp

to Ladner by collision configuration.



SW1223 – August 2015 70


The majority of the collisions that occurred at the Highway 99 SB Off-ramp to Ladner

are classified as rear-ends. Collision frequency of the four most common collision

configurations are shown in Figure 89. Approximately 52% of all rear end collisions



Figure 90 shows the overall severity of collisions near the Highway 99 SB Off-ramp to

Ladner.


The majority (57%) of the collisions that occurred near the Highway 99 SB Off-ramp to

Ladner resulted in “property-damage-only” collisions.

a report to for: george massey tunnel replacement project · a report to for: george massey tunnel...

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