No, not generally. The definitions call the Roll Cast “an Anchored Cast without a substantial change of direction”, and the guide gives a figure: “Roll casts are not generally good change of direction casts, and the longer the line the harder it is. With casts of around 40 feet, the greatest angle change that can be made is approximately 15 degrees before the delivery cast suffers.” Note both hedges: about 15 degrees at around 40 ft, and less as the line gets longer.

The reason is the 180 Degree Principle for anchored casts. The D Loop is the only part you can energize and the anchor holds the rest, so swinging the D Loop off the target line breaks the lateral alignment of anchor, D Loop and delivery. The delivery is then more likely to cross the anchor and collide.

When you genuinely need to change direction, use a cast built for it: a change of direction is what makes a Spey cast a Spey cast.

Source

From the CI Study Guide (2025) (PDF), Task 18; terms from the FFI Fly Casting Definitions (Roll Cast, Spey Cast).