Where speed limits are not posted, and where no special hazard exists, the following speed shall be lawful: twenty five (25) miles per hour on streets and highways and fifteen (15) miles per hour in alleys. It shall be unlawful for any person to drive any vehicle:
A. One to four (4) miles per hour over the unposted speed limit;
B. Five (5) to nine (9) miles per hour over the unposted speed limit;
C. Ten (10) to nineteen (19) miles per hour over the unposted speed limit;
D. Twenty (20) to thirty nine (39) miles per hour over the unposted limit;
E. Forty (40) miles per hour or more over the unposted speed limit. (1968 Code §§6-5-1, 6-5-2; Ord. 75-86; Ord. 90-24; Ord. 01-42; Ord. 03-49; Ord. 03-173)