Affect of the Interconnect crossing while making a layout (interconnect carrying voltage or current signals)

Hi,

I am making a certain layout. There are many interconnects crossing over each other (e.g. M2 crossing over M1). The interconnects are carrying voltage and current signals. 

I want to improve my layout. I don't know how the interconnect crossing effect my signals. More particularly, I wan to understand:

1) How the signals are affected when interconnect carrying a voltage signal cross over other interconnect carrying voltage signal?

2) How the signals are affected when interconnect carrying a current signal cross over other interconnect carrying current signal?

3) How the signals are affected when interconnect carrying a current signal cross over other interconnect carrying voltage signal?

4) For a long interconnect, is it prefer to send a current signal or a voltage signal and why?

If there is some known theory, I will be grateful if you share it with me.

Thanks and Regards,

Vishesh