Despite Chicago city officials’ efforts to reduce Mexican Independence Day car caravans this year, the annual festivities prompted the city to implement sudden road closures downtown Saturday evening. Many residents spent hours trying to get home. “(It was) an epic failure like I have never seen in this city. Not Nascar, (n)ot Lollapalooza, (n)ot anything compared to how poorly this was handled,” Aaron Thompson, a 46-year-old River North resident, wrote to Ald.