A display control device or a non-transitory computer-readable storage medium storing a display control program grasps information of an oncoming vehicle that is a passing target on a narrow road, causes a head-up display to perform overlapping display of a first assistance image with a foreground of a subject vehicle, the first assistance image assisting a driver in lateral position adjustment, and displays, on a screen display device, an external environment image in which a second assistance image that assists passing overlaps with a capture image.

A system and method of identifying and quantifying congestion within a traffic stream including obtaining telemetric data from a plurality of vehicles traveling within a plurality of normalized road segments, determining a property of each normalized road segment based on the telemetric data and a road profile for each road segment, determining a disruption score indicative of a level of disruption in a traffic flow within each road segment, mapping the road segments within a two-dimensional spatial-temporal grid of cells, wherein each cell represents a normalized road segment at a specified time, for each cell, determining if the traffic flow is congested, identifying a congested traffic stream including a plurality of contiguous cells that have congested traffic flow, quantifying the congested traffic stream, and providing an output signal.

A traveling vehicle system, in a merging area including a merging point, until a traveling vehicle traveling on one travel route passes through the merging area, stops a traveling vehicle traveling on another travel route at a stop point before the merging point. The traveling vehicle system calculates a required time for a first traveling vehicle passing through the merging point to pass through the merging area and, when a second traveling vehicle following the first traveling vehicle and traveling on the same travel route as the first traveling vehicle outside the merging area is capable of entering the merging area within the required time, causes the second traveling vehicle to enter the merging area without decelerating the second traveling vehicle to a speed limit or less enabling stopping at the stop point.