Answer:
The solution in python. 
Output:
    print("0 is not a valid interstate highway number")
Explanation:
h = int(input("enter highway number: ")) #take highway number
if(h>=1 and h<=99): #for primary highway
    if(h%2==0):
        print("I-%d is primary, going east/west" %h) #for even highway number 
    else:
        print("I-%d is primary, going north/south" %h) #for odd highway number
elif(h>=100 and h<=999): #for auxiliary highway
    aux=str(h) #convert into string for fetch the rightmost number
    l=len(aux) #find the length 
    val = aux[l-2]+aux[l-1] #assign value of rightmost two number
    h = int(val) #convert into integer
    if(h%2==0):
        print("I-"+aux+" is auxiliary,"+"serving I-%d, going east/west" %h)
    else:
        print("I-"+aux+" is auxiliary,"+"serving I-%d, going north/south" %h)
elif(h==0):#for 0 highway number
    print("0 is not a valid interstate highway number")
else:
    pass