Roadblock #4: Still on the hook for college

The problem: With couples having kids later in life, "those in their late fifties and early sixties are increasingly finding that retirement and education are battling for the same dollars," notes Marlton, N.J., financial planner Raymond Loewe.

College now runs $20,000 to $55,000 a year, and many parents are wary of saddling their kids with debt. But as Loewe points out, those near retirement "have to balance their desire to help with the possibility of being dependent on their children later in life."

Solution #1: Get square on your share. Use the AARP Retirement Nest Egg Calculator to see what you must set aside per year to retire as you'd like; play with the numbers to figure out how much tuition you can pay and still save enough.

Also, check out the College Board Expected Family Contribution calculator, which shows what portion of tuition schools will assume you can cover with income and savings. Don't plan on using 401(k)s and IRAs to pay for college, warns Mark Kantrowitz of FinAid.org. Normally, these are excluded from federal need analysis, but every dollar you withdraw counts as income, which may result in less aid.

Solution #2: Shop for a deal. When helping your child decide where to apply, use the school search tool at collegeboard.com to see what percentage of "need" -- the difference between your EFC and the full cost -- a school meets, and how. Focus on colleges that are generous with grants. Also, compare your kid to current students via the "How Do I Stack Up?" feature. Your child may get more aid at schools where he's a top-of-pack candidate, says Nancy Flint-Budde, a Salem, N.Y., financial planner.

Solution #3: Borrow smart. Plan to exhaust federal Stafford loans -- which are in the child's name and are fixed at 6.8% -- before taking a parent PLUS loan, at 7.9%.

But remember, you may be repaying the debt in retirement, so use an online loan calculator to determine the monthly payment before accepting loans. Terms on federal loans can sometimes be extended, to 30 years from 10, which can cut monthly payments up to 43% -- though you'll pay much more interest. In retirement, the income-based repayment option may also reduce your nut.