Sure! Here's some information for your planned road trip from Chicago to Milwaukee, Detroit, and Cleveland:

Best Time to Visit:
The ideal time to visit these cities is during the late spring, summer, and early fall (May through October). During this time, the temperatures are warm and numerous events are taking place.

Route and Accessibility:
You can start your trip in Chicago, then head north to Milwaukee (around 1.5 hours drive via I-94 W). From Milwaukee, Detroit is a 6-hour drive east (via I-94 E). Finally, from Detroit, you would head south-east to reach Cleveland, which is a 3-hour drive (via I-90 E).

Altitude and Acclimatization:
These cities are all close to sea level, so you won't have issues with altitude sickness.

Accommodation and Booking:
Book accommodations in advance, there is a wide range of options in all four cities from luxury hotels to budget-friendly lodgings.

Clothing and Essentials:
Pack according to the season in which you are visiting. Summer can get hot so pack light clothing, but always take a couple of jackets or sweaters as it can get cool in the evenings. Comfortable walking shoes are a must as these cities have lots of attractions to walk around. If you'll be near Lake Michigan or Lake Erie, you might want to pack a swimsuit as well.

Health and Safety:
Always have a plan for emergencies and keep your health insurance information handy. Follow traffic laws and always have a designated driver if drinking.

Local Etiquette and Respect:
Local customs in these cities are quite typical of the United States. Be polite, tip 15-20% in restaurants, and respect any local customs or rules in each city. Be sure to show respect to local cultures and traditions, as these cities have diverse populations with different backgrounds.