Excavations at Harappa, Mohenjo-daro, Kalibangan, Lothal and Dholavira show that Indus Valley cities were laid out on a grid pattern, with the main streets running north-south and east-west and cutting one another at right angles.

The city was typically divided into a raised citadel to the west (with structures like the Great Bath and granary) and a larger lower town to the east where residents lived, both drained by an elaborate covered drainage system running along the streets.

There is no evidence of large temple complexes as urban focal points, circular settlement plans or irregular winding lanes as the dominant pattern; these are features of other cultures.

Hence, the answer is streets intersecting at right angles.