An example of an actual commuter-dominant four year school would be California State University Dominguez Hills, where only 14% of frosh (and 5% of all undergraduates) live in campus housing.
In general, the percentage of frosh living in campus housing is better proxy for residential students, since a common pattern at many colleges is that residential frosh live in the dorms, but move to nearby off-campus housing in later years.
However, at some colleges, there are off-campus dorms specifically marketed to college students (including frosh). This may result in the frosh living in campus housing percentage underestimating the percentage of students who are residential.
At a few colleges, the norm is for undergraduates to live in campus housing all years, reflected by high percentages of all undergraduates living in campus housing.
Many colleges do have a mix of residential and commuter students. These include state universities which have a substantial draw for both local area students and non-local students. Some examples are state flagship universities in large metro areas of their states (e.g. University of Hawaii Manoa), or non-flagship state universities that serve commuters in their local areas but also have some other attraction (e.g. strength in popular majors or location) that pulls in non-local students (e.g. San Jose State University).