Weekend closures of the Don Valley Parkway and Gardiner Expressway as well as Line 1 TTC closures have commuters bracing for chaos; despite contingency plans, the TTC workers' union says a total disruption is possible if nearly 13,000 workers walk off the job; and, Consumer Reports says the most effective tick and mosquito repellents contain 25 to 30 per cent deet as their active ingredient.