Background Paragraph: Turner et al (2006) derived crash prediction models for this report’s predecessor and found a
pronounced ‘safety in numbers’ effect in the models. Using the crash prediction model for mid-block
locations, generic motorist and cyclist volumes can be used to demonstrate the impacts on the
expected crash rate of varying motor vehicle and cycle volumes. As shown in figure 2.20, an increase
in the proportion of cyclists to the overall traffic volume causes an increase in expected crashes at
mid-block locations, but the crash rate increases at a decreasing rate. That is to say, the crash rate per
cyclist goes down as the cycle volume increases. 
Story: There were a lot of motorcycles on Interstate 15 last week. On Saturday, there were 1551 motorcyclists. On Sunday, there were 2551 motorcyclists. On Monday, there were 3551 motorcyclists. On Tuesday, there were 4551 motorcyclists. On Wednesday, there were 5551 motorcyclists. On Thursday, there were 6551 motorcyclists. On Friday, there were 7551 motorcyclists. 
Question: What day had a lower crash rate per cyclist: Tuesday or Thursday?
Thursday.