DUI data, the legislature's disregard

According to statistics reported by the Department of Public Safety in 2015, 53% of auto deaths had no blood alcohol concentration (BAC) in the driver, 1.7% from .05-.07 BAC, 1.9% from .08-.15, and 5.5% at .16 and above. Of course it is always unfortunate when a person is killed in a drunk driving case, but the question is why is Utah changing the legal limit from .08 to .05 when there is close to no significance that it will make towards saving lives in a drunk driving incident? Why was the legislature so persistent in passing this and focusing on 1.7% and not focusing on the real problem, the 53% of auto deaths that had nothing to do with alcohol. This furthers the argument that the legislature does not create all laws based on facts and logic, but on personal morals that restricts the freedom of others. The economic impacts will be harsh unless we stop the abuse of power.