Here is a collection of links related to the use of Visual Occlusion.

• This is a YouTube link to John Senders’ seminal introduction in the 1960’s of the concept of using visual occlusion to study attentional workload in driving:  https://www.youtube.com/watch?v=kOguslSPpqo .(This is the corresponding published study:  J.W. Senders, A.B. Kristofferson, W.H. Levison, C.W. Dietrich, J.L. Ward: “The attentional demand of automobile driving.” Highway Research Record, No. 195, 1567, 15-33, 1967.)
• US National Highway Traffic Safety Administration (NHTSA): Visual-<anual Driver Distraction Guidelines for In-Vehicle Electronic Devices (See pp 275-279 for specific guidelines for occlusion experiments.)
• This link will bring you to the site for SAE Standard J2365: Calculation of the Time to Complete In-Vehicle Navigation and Route Guidance Tasks. (Note that you must pay ($70) to download that standard.)
• Michael Pettitt’s PhD thesis, “Visual Demand Evaluation Methods for In-Vehicle Interfaces”, which includes a review of various driver distraction evaluation methods, including visual occlusion, can be downloaded here.