I believe the Roadside Assistance tests are slightly different to the workshop tests.
Obviously, I'm not sure how, they seemed fun enough to me!

The day consisted of 6 1xhour tests.
Each test is overseen by an examiner.

Fault on TDCi (Ford Fusion - nonstart): using relevant equipment and Data, diagnose and rectify fault.
Fill out Customer assistance forms explaining diagnosis and repair.
Answer questions relating to diesel systems.

Electrical fault (Ford Focus PATS): Diagnose and rectify electrical fault on vehicle using relevant equipment and data.
Fill out Customer assistance forms explaining diagnosis and repair.
Answer questions relating to electrical systems.

Apprentice (Honda Civic Hybrid): guide an apprentice through a vehicle repair or vehicle system, explaining health and safety issues, safe working practices and also the relevant vehicle system whilst investigating fault.

Brake fault & customer focus (Vw Polo ABS): Diagnose and rectify (as required) brake fault on vehicle, using relevant equipment and data. Fill out Customer assistance forms explaining diagnosis and repair.
Explain fault and required repair with vehicle driver.
Answer questions relating to brake systems.

Fault on Engine system (Vx Zafira): Diagnose and rectify MIL on vehicle and repair using relevant equipment and data.
Fill out customer assistance form explaining diagnosis and repair.
Answer questions on emissions and fuel trim.

Online test: 30 multiple choice questions on the IMI website.
These were varied between CAN, HiD lighting, emissions, auto transmissions etc

There may have been more to it, I've just covered the basics.