Percolation on an isotropically directed lattice

We investigate percolation on a randomly directed lattice, an intermediate between standard percolation and directed percolation, focusing on the isotropic case in which bonds on opposite directions occur with the same probability. We derive exact results for the percolation threshold on planar lattices, and we present a conjecture for the value of the percolation-threshold in any lattice. We also identify presumably universal critical exponents, including a fractal dimension, associated with the strongly connected components both for planar and cubic lattices. These critical exponents are different from those associated either with standard percolation or with directed percolation.