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.)
• Visual-Manual NHTSA Driver Distraction Guidelines for In-Vehicle Electronic Devices (Docket No. NHTSA-2010-0053; p. 177). (n.d.). National Highway Traffic Safety Administration (NHTSA). Retrieved https://www.nhtsa.gov/sites/nhtsa.gov/files/distraction_npfg-02162012.pdf
• 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.)