Get-Direction.ps1

Function Get-Direction()
{

Param(
    [Parameter(Mandatory=$true,Position=0)] $Origin,
    [Parameter(Mandatory=$true,Position=1)] $Destination,
    [Parameter(Position=2)] [ValidateSet('driving','bicycling','walking')] $Mode ="driving",
    [Switch] $InMiles
    )
    
$Units='metric' # Default set to Kilometers

# If Switch is selected, use 'Miles' as the Unit
If($InMiles){$Units = 'imperial'}

#Requesting Web Page
$webpage = Invoke-WebRequest "https://maps.googleapis.com/maps/api/directions/xml?origin=$Origin&destination=$Destination&mode=$($mode.toLower())&units=$Units&key=AIzaSyAjkqgmCw15XhKat2Z-cIGZ-rzmE0xXHjc" -UseBasicParsing -ErrorVariable +err

# Capturing the HTML output
$content = $webpage.Content

#To Clear unwanted data from the String
    Function Clean-String($Str)
    {
        $str = $Str.replace('<div style="font-size:0.9em">','')
        $str = $str.replace('</div>','')
        $str = $str.replace('<b>','')
        $str = $str.replace('</b>','')
        $str = $str.replace('&nbsp;','')
        Return $str
    }

# Data Mining information from the XML content
$status = (Select-Xml -Content $content -xpath '//status').Node.InnerText

    If($status -eq 'OK')
    {
        $Mode = (Select-Xml -Content $content -xpath '//route/leg/step/travel_mode').Node.InnerText
        $Duration = (Select-Xml -Content $content -xpath '//route/leg/step/duration/text').Node.InnerText
        $Distance = (Select-Xml -Content $content -xpath '//route/leg/step/distance/text').Node.InnerText
        $Instructions = (Select-Xml -Content $content -xpath '//route/leg/step/html_instructions').Node.InnerText | %{ Clean-String $_}
        
        $Object = @()
        for($i=0;$i -le $instructions.count;$i++)
        {
        $Object += New-Object psobject -Property @{TravelMode=$Mode[$i];Duration=$Duration[$i];Distance= $Distance[$i];"Instructions"= $Instructions[$i]}
        }
        
        Return $Object
    }
    else
    {
        # In case the no data is recived due to incorrect parameters
        Write-Host "Zero Results Found :  Try changing the parameters" -fore Yellow
    }

}

Thanks for your valuable suggestions Jeff, I've revised the script accordingly.

DelaneyJM, well lot more to be done on this ;), we can modify the function identify all possible alternatives, which includes Public transit as well

I think I just identified a pull request :)

Line 17 ends with
-ErrorVariable +err
What does the + character do?

'+' is used to add the next error to the same error variable, making it a type of Error Object Array.
TRY THIS -

Invoke-WebRequest "badurl.com" -ErrorVariable +err
$err

then again the same commands and see how error messages are added to same array :)

Thanks. It seems I learn new things about PowerShell every day for the past 6 years.

Is the use of -ErrorVariable left in the function for debugging purposes? The value of $err is not used by the function itself.

Also, what is the text that flashes on screen when I run the function?
It disappears so fast that I can't read it. It is a side-effect of the Invoke-WebRequest call.

The &key= clause shown below
$webpage = Invoke-WebRequest "https://maps.googleapis.com/maps/api/directions/xml?origin=$Origin&destination=$Destination&mode=$($mode.toLower())&units=$Units&key=AIzaSyAjkqgmCw15XhKat2Z-cIGZ-rzmE0xXHjc" -UseBasicParsing -ErrorVariable +err
can be omitted.
I have reformatted that logic to become:
$url = 'https://maps.googleapis.com/maps/api/directions/xml?'
$url += "origin=$Origin"
$url += "&destination=$Destination"
$url += "&mode=$($mode.toLower())"
$url += "&units=$Units"
$Parameters = @{
Uri = $url
UseBasicParsing = $true
}
$webpage = Invoke-WebRequest @parameters

Great work