ModelSamplingDiscrete_motorway_edition

ModelSamplingDiscrete_motorway_edition is the Motorway-pack version of ComfyUI's ModelSamplingDiscrete: it swaps a model's discrete sigma schedule - say, SD1.5's eps for a v_prediction or LCM model - but reads the model from the MOTORWAY 🚌💨 bus by key instead of over a wire.

The native node is one of the more useful ModelSampling tools, because a surprising number of broken-image problems are just a prediction-type mismatch. The sampling dropdown chooses the family: eps (the classic SD1.5/SDXL default), v_prediction, lcm (for distilled LCM checkpoints - this is the node that makes an LCM model actually behave), or x0. The zsnr toggle is the other classic: enable it to fix the washed-out, over-bright results you get when a model was trained with zero-SNR and sampled without it. It's the node behind a chunk of "why do my images look grey?" fixes.

What the motorway edition changes

Generated by clone_nodes_in_the_dangerzone/nodes.py, so the interface is: MOTORWAY 🚌💨 in (required), the native widgets (sampling, zsnr), and two key strings:

• INPUT_model_key (default model) - bus key holding the model to re-schedule.
• OUTPUT_MODEL_key (default MODEL) - bus key the re-scheduled model is written to.

It pulls the model out, applies the schedule, stores the result back under MODEL, and outputs only the cloned bus. Pull MODEL off with a Motorway 0x1 to feed the sampler. Functionally identical to the native node, just bus-native.

Installing

cd ComfyUI/custom_nodes
git clone https://github.com/agilly1989/ComfyUI_agilly1989_motorway

or ComfyUI Manager → "ComfyUI_agilly1989_motorway", restart. No pip deps, no model files.

The fragility you should know about

Same caveats as the whole _motorway_edition family: it's an auto-generated clone from the pack's self-described danger zone. The generator iterates every node ComfyUI has registered at import time, which is how a 2025 user hit a startup crash - an unrelated RandomModelClipVae class lacking a CATEGORY attribute killed the entire Motorway import. And the 1.1.7 hotfix disabled the clone loader entirely, so on current versions this node may simply not appear in your menu.

If you're not running a Motorway graph, skip it and use the native ModelSamplingDiscrete - particularly if you just want zsnr, which is genuinely one of the highest-value one-toggles in ComfyUI.