Lead route guidance system, portable route lead guidance device, and program

A portable route lead guidance device, comprising:

• a display screen to display a route guidance image;
• an acceleration detecting device to detect acceleration;
• a route storage memory to store a route from a starting point to a destination, and to store a guidance point located on the route at which guidance is provided to the user;
• and
• a controller, the controller comprising:
• a route guidance image creator to create a route guidance image including a route image specifying the route, and to create a lead image showing a lead position on the route ahead of a user's current position to lead the route;
• a walk detector to detect the user's walking based on the acceleration detected by the acceleration detecting device;
• a lead position updater to update the lead position in accordance with the user's walking as the user's walking is detected by the walk detector, wherein the lead position updater includes a lead position calculator that calculates a moving distance of the lead position based on a predetermined time period during which walking is detected by the walk detector and a preset moving speed of the lead position, and the lead position updater updates the lead position based on the calculated moving distance of the lead position;
• a guidance point arrival judger to judge whether the lead position arrives at the guidance point on the route;
• and
• wherein the lead position updater suspends updating of the lead position as the lead position arrives at the guidance point.