The Stockholm Bypass (FFS) tunnel has been scheduled to commence construction in 2013 and will pass on the western side of Stockholm city centre. The tunnel will be approximately 18 km in length and the interior design is expected to affect the drivers experiences pertaining drowsiness, arousal, distraction and feelings of safety and security. This study examines drivers experiences of the interior design of the tunnel in VTIs driving simulator III in Linköping. The study had 24 participants where 12 were men and 12 were women, with an age range of 30-45 years old. The study was performed at VTI driving simulator in Linköping. The tunnel that was studied was based on the blue-prints of the FFS tunnel (version FST Plan 2011-11-08). The results of the lateral position measure generally suggested large statistical effects, however, in practical terms; the mean values were relatively small. There were however, a number of inadvertent lane departures by two of the participants. Inadvertent lane departures are a safety concern, but there is too little data in this study to draw any conclusions concerning the tunnel design. A limited effect of the tunnels interior design was found in section 7, with male drivers only, where an improved (more centred) cornering line in the bend of section 7 was found, when the supporting ceiling lighting was present. Eye tracking analyses of the sections of the tunnel with supporting ceiling lighting were compared to the same sections of tunnel without the lighting. The mean glance duration was 234.3 ms without the lighting and 445.3 ms in the tunnel with the ceiling lighting and was significantly longer but should nevertheless be seen as mild from a traffic safety perspective. When specifically asked about their preferences, the 58 per cent of the participants preferred the tunnel with the ceiling lighting, 29 per cent preferred the tunnel without the ceiling lighting and 13 per cent didnt prefer one tunnel design more than the other. In summary, a good rating of approval for the tunnel design concept in the opinion of the participants.