After crossing the Poplar Street Bridge, I-64 splits off, while I-55 and I-70 stay concurrent. When they intersect I-270, I-55 stays on its own pavement using the mileposts from the Poplar Street Bridge, while I-70 heads east on I-270's pavement using I-270's mileposts. So when I-55/70 intersects I-270 from the southeast, the exit numbers would be 20 A/B, whereas if I-70 intersects I-55/270 from the east, it would be exits 15 A/B.
I-70 does not pass through any major cities in Illinois. It does run concurrent with Interstate 57 around Effingham. I-70 then proceeds east towards Indiana.
Interstate 70 Illinois Descriptions - I70.mobi
