It is advantageous to arrive in France early enough to become familiar with the different foods, road and sign system, and culture in general. A minimum of 5 days may be needed to overcome the effects of jetlag. I found the French diet to be so different from my normal diet that I needed a substantial increase in caloric intake to maintain weight. This may change sometime after sufficient exposure. Many of the European riders belong to clubs and ride together the entire route.
Mechanical problems are often easier to solve with a small group than alone.
Food and drink can be shared in a group, and the conversation will help keep a rider from feeling like dropping out during periods of depression. A group is much less likely to stray from the course or miscalculate a controls closing time. The groups headlights help locate turns and is safer than a single light. Training for PBP will vary with a person's specific goals. The rider trying to finish in the front group must be ready to handle the pace of a typical European roadrace.