Windshield wipers are the lowest-cost safety maintenance item on a car and the most commonly deferred beyond their useful service life. A wiper blade that streaks, skips, or leaves areas of the windshield uncleared reduces visibility in rain to a level that slows reaction time in ways that have been documented in wet weather accident statistics. The replacement cost is $20 to $50 for a complete set of wiper blades. The installation takes five minutes with no tools. The safety return on this investment is among the highest available in automotive maintenance.