Question: Is there a relationship between vehicle damage and collision type in car crashes?

My project will be using data from a dataset that covers car crashes and their variables. I will be using statistical methods to evaluate the relationship between collision type and the damage to a vehicle after an accident. In my dataset there are 39 variables total, and 205539 cases. The data frame collects data from car crashes that have happened in Montgomery county.

Link to the dataset: https://catalog.data.gov/dataset/crash-reporting-drivers-data

Data Analysis In order to address my research question, I should group my prime variables together into one dataset to make comparisons on the severity and extent of vehicle damage. This will also be helpful because inside the damage variability there is range in the severity of vehicle damage by different categories.

##Check structure, and create new data using the variables collision type and vehicle damage to compare

str(dataset)
## 'data.frame':    205539 obs. of  39 variables:
##  $ Report.Number                : chr  "MCP3296002G" "MCP276700BF" "MCP32790038" "MCP34000014" ...
##  $ Local.Case.Number            : chr  "240018653" "240012321" "240022955" "240019831" ...
##  $ Agency.Name                  : chr  "MONTGOMERY" "MONTGOMERY" "MONTGOMERY" "MONTGOMERY" ...
##  $ ACRS.Report.Type             : chr  "Property Damage Crash" "Property Damage Crash" "Property Damage Crash" "Property Damage Crash" ...
##  $ Crash.Date.Time              : chr  "04/21/2024 06:53:00 PM" "03/14/2024 05:23:00 PM" "05/15/2024 07:30:00 AM" "04/28/2024 05:30:00 PM" ...
##  $ Route.Type                   : chr  "County Route" "US (State)" "Maryland (State) Route" "County Route" ...
##  $ Road.Name                    : chr  "" "COLUMBIA PIKE (SB/L)" "VEIRS MILL RD (WB/L)" "HARDING DR" ...
##  $ Cross.Street.Name            : chr  "" "" "" "" ...
##  $ Off.Road.Description         : chr  "" "" "" "" ...
##  $ Municipality                 : chr  "" "" "" "" ...
##  $ Related.Non.Motorist         : chr  "" "" "" "" ...
##  $ Collision.Type               : chr  "Sideswipe, Opposite Direction" "Sideswipe, Same Direction" "Front to Rear" "Front to Rear" ...
##  $ Weather                      : chr  "Clear" "Clear" "Clear" "Clear" ...
##  $ Surface.Condition            : chr  "Dry" "Dry" "" "Dry" ...
##  $ Light                        : chr  "Daylight" "Daylight" "Daylight" "Daylight" ...
##  $ Traffic.Control              : chr  "No Controls" "No Controls" "No Controls" "No Controls" ...
##  $ Driver.Substance.Abuse       : chr  "Unknown, Unknown" "Unknown, Unknown" "Unknown, Unknown" "Unknown, Unknown" ...
##  $ Non.Motorist.Substance.Abuse : chr  "" "" "" "" ...
##  $ Person.ID                    : chr  "8F256727-5915-4435-9CE7-5F2D943B8DCA" "BB361322-2BD1-47AE-B6B4-9359BAE743A5" "E04C495C-1DE3-4AC9-B507-A9B2C207056C" "D7E62A5D-C733-490D-AC9C-B5EA089C651E" ...
##  $ Driver.At.Fault              : chr  "No" "No" "No" "No" ...
##  $ Injury.Severity              : chr  "" "No Apparent Injury" "" "" ...
##  $ Circumstance                 : chr  "" "" "" "" ...
##  $ Driver.Distracted.By         : chr  "" "" "" "" ...
##  $ Drivers.License.State        : chr  "" "" "" "" ...
##  $ Vehicle.ID                   : chr  "FDDB5331-EC22-41B2-9143-124692C70CF6" "7EDA4B0A-1880-4BC7-AB71-DBE62C3A9801" "BBAC2C29-9197-40D8-9B22-9156FA82B6F1" "3ACB0037-C9D5-48C5-B410-BE986F22CA86" ...
##  $ Vehicle.Damage.Extent        : chr  "Disabling" "Vehicle Not at Scene" "Vehicle Not at Scene" "Functional" ...
##  $ Vehicle.First.Impact.Location: chr  "Eleven O Clock" "Vehicle Not at Scene" "Vehicle Not at Scene" "One O Clock" ...
##  $ Vehicle.Body.Type            : chr  "Passenger Car" "Passenger Car" "Passenger Car" "Passenger Car" ...
##  $ Vehicle.Movement             : chr  "Turning Left" "Overtaking/Passing" "Moving Constant Speed" "Moving Constant Speed" ...
##  $ Vehicle.Going.Dir            : chr  "Northbound" "Southbound" "Northbound" "Southbound" ...
##  $ Speed.Limit                  : int  25 45 45 25 35 35 40 30 5 30 ...
##  $ Driverless.Vehicle           : chr  "No" "No" "No" "No" ...
##  $ Parked.Vehicle               : chr  "No" "No" "No" "No" ...
##  $ Vehicle.Year                 : int  2013 0 2006 2012 2015 0 2015 2006 0 2014 ...
##  $ Vehicle.Make                 : chr  "HYUNDAI" "" "CHEVROLET" "NISSAN" ...
##  $ Vehicle.Model                : chr  "SONATA" "" "COBALT" "ALTIMA" ...
##  $ Latitude                     : num  39.1 39 39.1 39 39.1 ...
##  $ Longitude                    : num  -77 -77 -77.1 -77 -77.1 ...
##  $ Location                     : chr  "(39.10533874, -76.98984545)" "(39.04000338, -76.99722287)" "(39.0730963, -77.1112541)" "(39.02194389, -77.01829961)" ...
ds2 <- table(dataset$Collision.Type, dataset$Vehicle.Damage.Extent)
ds2
##                                
##                                 DESTROYED Disabling DISABLING Functional
##   Angle                                 0      4292         0       1385
##   ANGLE MEETS LEFT HEAD ON             37         0       367          0
##   ANGLE MEETS LEFT TURN               123         0       977          0
##   ANGLE MEETS RIGHT TURN               33         0       504          0
##   Front to Front                        0      1303         0        321
##   Front to Rear                         0      3186         0       3021
##   HEAD ON                             541         0      1816          0
##   HEAD ON LEFT TURN                  1048         0      7881          0
##   N/A                                  10         0       113          0
##   OPPOSITE DIR BOTH LEFT TURN           8         0       116          0
##   OPPOSITE DIRECTION SIDESWIPE        108         0       862          0
##   Other                                 0       991         0        427
##   OTHER                               422         0      3442          0
##   Rear To Rear                          0        55         0         92
##   Rear To Side                          0       885         0        277
##   SAME DIR BOTH LEFT TURN               1         0        83          0
##   SAME DIR REAR END                  1336         0     16426          0
##   SAME DIR REND LEFT TURN              26         0       249          0
##   SAME DIR REND RIGHT TURN             19         0       160          0
##   SAME DIRECTION LEFT TURN             56         0      1064          0
##   SAME DIRECTION RIGHT TURN            58         0       804          0
##   SAME DIRECTION SIDESWIPE            209         0      2950          0
##   Sideswipe, Opposite Direction         0       448         0        306
##   Sideswipe, Same Direction             0       915         0       1300
##   Single Vehicle                        0      1954         0        485
##   SINGLE VEHICLE                     1925         0      7840          0
##   STRAIGHT MOVEMENT ANGLE            1639         0     16639          0
##   Unknown                               0        56         0         27
##   UNKNOWN                              11         0        61          0
##                                
##                                 FUNCTIONAL   N/A No Damage NO DAMAGE OTHER
##   Angle                                  0     0        17         0     0
##   ANGLE MEETS LEFT HEAD ON             169     2         0        12     0
##   ANGLE MEETS LEFT TURN                589     1         0        17     0
##   ANGLE MEETS RIGHT TURN               393     0         0        18     1
##   Front to Front                         0     0         1         0     0
##   Front to Rear                          0     0        46         0     0
##   HEAD ON                              675     0         0        60     0
##   HEAD ON LEFT TURN                   2697     9         0        74     5
##   N/A                                   81     9         0       123     3
##   OPPOSITE DIR BOTH LEFT TURN           90     0         0        11     0
##   OPPOSITE DIRECTION SIDESWIPE         632     2         0       106     1
##   Other                                  0     0        17         0     0
##   OTHER                               4276    83         0      1932    20
##   Rear To Rear                           0     0         7         0     0
##   Rear To Side                           0     0        10         0     0
##   SAME DIR BOTH LEFT TURN              182     3         0        35     0
##   SAME DIR REAR END                  18341    91         0      1620    18
##   SAME DIR REND LEFT TURN              203     0         0        16     0
##   SAME DIR REND RIGHT TURN             215     2         0        31     0
##   SAME DIRECTION LEFT TURN            1170    11         0        81     2
##   SAME DIRECTION RIGHT TURN           1106     8         0       128     2
##   SAME DIRECTION SIDESWIPE            4199    41         0       633     9
##   Sideswipe, Opposite Direction          0     0         9         0     0
##   Sideswipe, Same Direction              0     0        41         0     0
##   Single Vehicle                         0     0       205         0     0
##   SINGLE VEHICLE                      2386    32         0       969    24
##   STRAIGHT MOVEMENT ANGLE             7499    18         0       361    17
##   Unknown                                0     0        15         0     0
##   UNKNOWN                               90     4         0        17     0
##                                
##                                 Superficial SUPERFICIAL UNKNOWN
##   Angle                                 961           0       0
##   ANGLE MEETS LEFT HEAD ON                0         101      12
##   ANGLE MEETS LEFT TURN                   0         296      30
##   ANGLE MEETS RIGHT TURN                  0         234      21
##   Front to Front                        218           0       0
##   Front to Rear                        3149           0       0
##   HEAD ON                                 0         597      97
##   HEAD ON LEFT TURN                       0        1109     103
##   N/A                                     0         178      68
##   OPPOSITE DIR BOTH LEFT TURN             0          89       8
##   OPPOSITE DIRECTION SIDESWIPE            0         998     174
##   Other                                 480           0       0
##   OTHER                                   0        7180    1675
##   Rear To Rear                          162           0       0
##   Rear To Side                          344           0       0
##   SAME DIR BOTH LEFT TURN                 0         360      55
##   SAME DIR REAR END                       0       16378    1549
##   SAME DIR REND LEFT TURN                 0         219      30
##   SAME DIR REND RIGHT TURN                0         264      29
##   SAME DIRECTION LEFT TURN                0        1192     139
##   SAME DIRECTION RIGHT TURN               0        1513     213
##   SAME DIRECTION SIDESWIPE                0        6924    1262
##   Sideswipe, Opposite Direction         337           0       0
##   Sideswipe, Same Direction            2246           0       0
##   Single Vehicle                       1015           0       0
##   SINGLE VEHICLE                          0        2357     339
##   STRAIGHT MOVEMENT ANGLE                 0        3750     419
##   Unknown                                40           0       0
##   UNKNOWN                                 0         138     397
##                                
##                                 Vehicle Not at Scene
##   Angle                                          205
##   ANGLE MEETS LEFT HEAD ON                         0
##   ANGLE MEETS LEFT TURN                            0
##   ANGLE MEETS RIGHT TURN                           0
##   Front to Front                                  74
##   Front to Rear                                  614
##   HEAD ON                                          0
##   HEAD ON LEFT TURN                                0
##   N/A                                              0
##   OPPOSITE DIR BOTH LEFT TURN                      0
##   OPPOSITE DIRECTION SIDESWIPE                     0
##   Other                                          153
##   OTHER                                            0
##   Rear To Rear                                    81
##   Rear To Side                                    86
##   SAME DIR BOTH LEFT TURN                          0
##   SAME DIR REAR END                                0
##   SAME DIR REND LEFT TURN                          0
##   SAME DIR REND RIGHT TURN                         0
##   SAME DIRECTION LEFT TURN                         0
##   SAME DIRECTION RIGHT TURN                        0
##   SAME DIRECTION SIDESWIPE                         0
##   Sideswipe, Opposite Direction                  120
##   Sideswipe, Same Direction                      694
##   Single Vehicle                                 239
##   SINGLE VEHICLE                                   0
##   STRAIGHT MOVEMENT ANGLE                          0
##   Unknown                                        111
##   UNKNOWN                                          0
###I can now see the collision type side by side under the categories of vehicle damage
summary(dataset)
##  Report.Number      Local.Case.Number  Agency.Name        ACRS.Report.Type  
##  Length:205539      Length:205539      Length:205539      Length:205539     
##  Class :character   Class :character   Class :character   Class :character  
##  Mode  :character   Mode  :character   Mode  :character   Mode  :character  
##                                                                             
##                                                                             
##                                                                             
##  Crash.Date.Time     Route.Type         Road.Name         Cross.Street.Name 
##  Length:205539      Length:205539      Length:205539      Length:205539     
##  Class :character   Class :character   Class :character   Class :character  
##  Mode  :character   Mode  :character   Mode  :character   Mode  :character  
##                                                                             
##                                                                             
##                                                                             
##  Off.Road.Description Municipality       Related.Non.Motorist
##  Length:205539        Length:205539      Length:205539       
##  Class :character     Class :character   Class :character    
##  Mode  :character     Mode  :character   Mode  :character    
##                                                              
##                                                              
##                                                              
##  Collision.Type       Weather          Surface.Condition     Light          
##  Length:205539      Length:205539      Length:205539      Length:205539     
##  Class :character   Class :character   Class :character   Class :character  
##  Mode  :character   Mode  :character   Mode  :character   Mode  :character  
##                                                                             
##                                                                             
##                                                                             
##  Traffic.Control    Driver.Substance.Abuse Non.Motorist.Substance.Abuse
##  Length:205539      Length:205539          Length:205539               
##  Class :character   Class :character       Class :character            
##  Mode  :character   Mode  :character       Mode  :character            
##                                                                        
##                                                                        
##                                                                        
##   Person.ID         Driver.At.Fault    Injury.Severity    Circumstance      
##  Length:205539      Length:205539      Length:205539      Length:205539     
##  Class :character   Class :character   Class :character   Class :character  
##  Mode  :character   Mode  :character   Mode  :character   Mode  :character  
##                                                                             
##                                                                             
##                                                                             
##  Driver.Distracted.By Drivers.License.State  Vehicle.ID       
##  Length:205539        Length:205539         Length:205539     
##  Class :character     Class :character      Class :character  
##  Mode  :character     Mode  :character      Mode  :character  
##                                                               
##                                                               
##                                                               
##  Vehicle.Damage.Extent Vehicle.First.Impact.Location Vehicle.Body.Type 
##  Length:205539         Length:205539                 Length:205539     
##  Class :character      Class :character              Class :character  
##  Mode  :character      Mode  :character              Mode  :character  
##                                                                        
##                                                                        
##                                                                        
##  Vehicle.Movement   Vehicle.Going.Dir   Speed.Limit    Driverless.Vehicle
##  Length:205539      Length:205539      Min.   : 0.00   Length:205539     
##  Class :character   Class :character   1st Qu.:25.00   Class :character  
##  Mode  :character   Mode  :character   Median :35.00   Mode  :character  
##                                        Mean   :32.19                     
##                                        3rd Qu.:40.00                     
##                                        Max.   :75.00                     
##  Parked.Vehicle      Vehicle.Year  Vehicle.Make       Vehicle.Model     
##  Length:205539      Min.   :   0   Length:205539      Length:205539     
##  Class :character   1st Qu.:2006   Class :character   Class :character  
##  Mode  :character   Median :2012   Mode  :character   Mode  :character  
##                     Mean   :1965                                        
##                     3rd Qu.:2016                                        
##                     Max.   :9999                                        
##     Latitude       Longitude        Location        
##  Min.   :37.72   Min.   :-79.49   Length:205539     
##  1st Qu.:39.02   1st Qu.:-77.19   Class :character  
##  Median :39.07   Median :-77.11   Mode  :character  
##  Mean   :39.08   Mean   :-77.11                     
##  3rd Qu.:39.14   3rd Qu.:-77.04                     
##  Max.   :39.99   Max.   :-75.53
##mostly categorical variables in this dataset, besides vehicle year, speed limit
dataset <- dataset |>
  mutate(dataset$Vehicle.Damage.Extent, recode(Vehicle.Damage.Extent,
                                                         "DISABLING" = "Disabling",
                                                         "FUNCTIONAL" = "Functional",
                                                         "NO DAMAGE" = "No Damage",
                                                         "SUPERFICIAL" = "Superficial"))
##combine vehicle damages in the same category into one column

Ho: Collision type and vehicle damage are independent to each other

Ha: Collision type and vehicle damage are related/dependent upon each other

##Chi square test of independence between collision type and vehicle damage
chisq.test(ds2)
## Warning in chisq.test(ds2): Chi-squared approximation may be incorrect
## 
##  Pearson's Chi-squared test
## 
## data:  ds2
## X-squared = 288012, df = 336, p-value < 2.2e-16

Statistical Analysis The p-value is approxiamte, but still extremely close to 0, proving the alternative hypothesis to be true, leading us to reject the null claim that vehicle collision and vehicle damage are not connected. At the (default) 5% significance level we can conclude that collision type and vehicle damage do share a relationship in car crashes based on the chi test.

Conclusion My chi square test was able to prove that my alternative hypothesis was correct, which was my projection about my project. The findings make sense because the severity, speed, and direction cars crash have a direct impact on the damage of a car. This proves why a fender bender might just end up with scratches on a car, while a t-bone may result in permanent damage to a car’s engine, coolant and oil, etc.

For further analysis or research, I could find a dataset that includes the speed a person was going at the time of a crash, which could further prove how collision type and vehicle damage are related in car crashes, because the faster you go, the more severe the crash may be. This can also be proved through statistical analysis.

##Car crash dataset source https://catalog.data.gov/dataset/crash-reporting-drivers-data ##Data function library for data cleaning https://github.com/rstudio/cheatsheets/blob/main/data-transformation.pdf