Using the Layers Palette
The Layer Palette works very much like the Surveyor Classic version.
The main differences are that the Layer Palette can now be positioned wherever you want on the screen, and the Add, Delete, Rename, and Merge options are now accessible from the right-click Contextual Menu.
New Layers
S20 lists the Ground Height and Ground Texture Layers at the top of the Layer List. These two layers were previously included within the topmost Route Layer. They have now been exposed in the UI to indicate that they are always at the top level, and cannot be moved, locked, hidden, edited or merged.

Additionally, a new Effect Layer group has been added which also operates above the Route Layer level.
Layer List
The Layer Palette is composed of a single layers list. The layers are ordered based on their (non-user-visible) internal numeric index. This places the route layers at the top of the list and the session layers at the bottom.

Each list row represents a single layer, and a single separator row is present dividing the route layers from the session layers.

Layer rows may be selected. When a single layer row is selected, that row becomes the Active Layer.

Multiselection is permitted, allowing you to merge or delete several layers in one operation.
Show/Hide and Lock/Unlock
Each layer row shows two icons - the Show/Hide icon, and the Lock/Unlock icon. You do not need to select a row in order to change its status.

The Show/Hide icon will toggle the visibility of the target layer, and the Lock/Unlock icon will disable editing of objects on that layer.

Objects that are within a hidden layer cannot be selected, but will still be copied along with your Marquee Selection if duplicated or saved as a Scrapbook. In other words, if you select and make the scrapbook while the objects are visible, hiding them will not prevent them being pasted. Hiding them before you make the selection will prevent them being selected and therefore copied.

Objects within a Locked layer cannot be moved but can be copied.
Hiding a layer does not prevent objects from being copied or deleted by any copy/paste operations.
Add New Layer
Click on the + icon on the Effect, Route, or Session title rows to add a new layer.
Managing Layers
Layers can be reordered by clicking and dragging on the layer row anywhere except the interactive visibility/lock buttons.

When multiple layers are selected, the entire selection set will be reordered by such an operation. If there are gaps in the selection, they will be contracted before the reorder operation.

Right clicking on a layer row shows a contextual menu with the following commands:

* Rename Layer...
* Delete Layer... / Delete Layers...
* Merge Layer Into... (Only when a single layer is selected.)
* Combine Selected Layers. (Only when multiple layers are selected.)
* Lock/Unlock Entire Route
Current Layer
The Palette Title shows the currently selected (active) layer. E.g. "Layers - Route Layer" where "Route Layer" is the name of the active layer.

The active layer is used for all object/track/train placement, however Ground and Ground Texture changes are always saved to their respective layers.
When selecting an object in the world, the Info Palette displays the layer that the object belongs to. This can, of course, be different to the selected (active) layer.

You can change an object's layer by expanding the Layer menu in the Info Palette, and choosing its layer through the dropdown.
Info Palette
The Info Palette also provides a variety of layer options.