All, some or none of the following rules can be added into the D&D chariot race. Feel free to experiment, and use only the rules you like. Be aware, however, that these rules do change the strategy of the races.
Using These Rules with D&D 3.5 or 4.0
The chariot race rules were originally written for Original Edition D&D, and its many clones, and work well, as is, with AD&D 1st edition and second edition. However, they can be used with editions 3.0, 3.5 and 4.0 perfectly well, simply by making this adjustment: Any saving throws or charioteering skill checks called for in these rules simply become Reflex saves made against a Difficulty Class of 15, and modified as listed.
The game master is, of course, free to allow a Chariot Driving skill in the game, and this should probably be done if the rules are going to be used on a regular basis. However, if such a skill is in play, the checks are made against a Difficulty Class of 20, instead of 15.