Possible Clues:

• A viewer's problem crossing road block
• Hinder progress
• Thwart — my ties (anag)
• Snooker break is met with difficulty in the end
• Tricky situation -- my tie's getting loosened
• This person's reversing in street that is creating obstructive situation
• Block; hinder
• Block and pen belonging to the writer, not new
• Check ties? My clobber!
• Thwart or block