Related Clues:

• Widen
• Motorist's aid
• Roadside beacon
• Sign of distress
• Signal for help
• 'Accident ahead' indicator
• Become wider
• Suddenly intensify, with "up"
• Outburst of violence
• Burst of light
• Roadside alert
• Distress signal shot into the air
• Bell-bottoms feature
• Sign of danger
• ''Breakdown ahead'' warning