Low latency IP direct connection over ISDN

Hi,

I want to connect two sites in Germany with minimal latency under low
bandwidth requirements. Both sides have numbers with the same area code.

It seems that all data on ADSL2+ lines is routed to a central exchange
several hundred kilometres away and thus latency is more than 60 ms (one
site is far away from the DSLAM and only has a 384 Kbit/s connection).
Can latency be improved via ISDN (I've read contradicting statements
about this)? My theory is that a direct ISDN connection (with itund)
would be routed within the same regional area and not sent to a central
internet exchange.

Regards,
Matthias-Christian