Same Interchange, Different Exit Numbers

[kurumi]

San Jose, CA, on I-880 Southbound (sign goofs, to be honest though)

Brokaw Road, exit 4B and exit 5
First Street, exit 4A and exit 389
The Alameda, exit 1D and exit 2

That 389 probably is... but I think the others have to do with CalTrans putting the exit number divisions at the .5 mile (Exit 1 is MP 0-1.5, 2 is 1.5-2.5, 3 is 2.5-3.5, etc), so the exit midpoints might fall on the divisions.

I would agree, but all signs listed are in the same (southbound) direction.

[roadfro]

Nevada has two examples, both in the Las Vegas area:

I-15 @ D St & Washington Ave. Exit 43 NB / Exit 44 SB
https://www.google.com/maps/@36.1811924,-115.1449624,16.73z

CC-215 @ Durango Dr & Sunset Rd. Exit 17 WB / Exit 18 SB
https://www.google.com/maps/@36.0703813,-115.2815189,16.23z

In both cases, these are split-diamond interchanges with ramps connected by frontage roads. The freeway milepost happens to be between the two cross streets. (In the I-15 example, previous BGSs signed exit 43 for D St only and exit 44 for Washington Ave only.)