Heavy Goods Vehicles (HGVs) present a significant risk to Vulnerable Road Users (VRUs), including cyclists and pedestrians, due to extensive blind spots. While overall road fatalities in the EU and UK have declined by 22% from 2010 to 2023, the number of HGV-related VRU fatalities remains disproportionately high. This study evaluates the direct vision capabilities of North American HGVs using the UNECE 167 regulation, a standard developed to enhance direct vision through digital human modelling (DHM) and volumetric analysis. The research examines the blind spots of selected North American HGVs using CAD-based assessment methods. Three vehicles, a Peterbilt 389, an International LT, and a LION 6 electric truck, were analysed using 3D scanning and DHM techniques to assess visibility. Results indicate that while North American cab-over-engine designs generally provide better visibility, significant blind spots remain, particularly in front of and beside the vehicles. The Peterbilt exhibited the largest frontal blind spot, while the International LT showed poor nearside visibility. The LION 6 demonstrated good frontal vision but performed poorly in nearside visibility, similar to tall EU trucks. Findings highlight the need for adaptations of UNECE 167 to better fit North American vehicle designs and regulations. Additionally, the study underscores the value of DHM systems in improving vehicle safety analysis. Ongoing research aims to expand the vehicle sample to refine blind spot measurement and propose design enhancements for improved VRU safety.