ONE OF THE WORST Election Day surprises for many voters comes when they are hit with a string of questions on the ballot, written in legalese and begging for instant analysis. Because a little advance work can go a long way toward eliminating voter's-booth embarrassment, Fairfax County residents may wish to read up on five bond questions they'll be asked on Nov. 4.

The proposed bond issue projects were selected by a review task force of citizens as the most pressing and worthy from a list submitted by the county government. The question is how best to finance these projects, since they could proceed as regular budget items if bonds -- a more prudent approach -- aren't approved. County financial experts say the local government is healthy enough to absorb these bond issues without any increase in the tax rate and that the bonds can be sold at a rate lower than that of inflation.That's more appealing than dipping into current income, or rejecting all the proposals and in effect putting off all action until a more expensive day.

So, from a financial standpoint, prudent residents may responsibly vote "YES" in all five instances. But one proposal, to expand the detention center, has drawn vigorous opposition from groups favoring alternative approaches; a "NO" vote to this question would permit futher study.

1. Neighborhood Improvement: $12.3 million. This project would help to bring older neighborhoods up to the standards of new subdivisions, widening roads, providing sidewalks for safe access to schools and stores and installing curbs, gutters, storm sewers and street lights in areas that initiate requests and share costs. This is a sensible, cooperative arrangement. YES.

2. Storm Drainage Improvements: $12 million. This is to eliminate serious flooding problems, with water detention ponds, protection walls and other improvements. This list is limited to top-priority projects. YES.

3. Public Safety Facilities: $19.7 million. The county would build three new fire stations, a new fire-fighter training facility and two police stations, and would renovate a maintenance garage and the old courthouse. The improvements would embrace all parts of the county. YES.

4. The Adult Detention Center: $8.55 million. This would finance renovation and enlargment of the detention center that was built two years ago, which the sheriff says has been overcrowded ever since. There is no question that the center has been packed, but opponents urge changes in the entire penal procedure, starting with replacement of the elected-sheriff system in favor of one that would put responsibility for incarceration in the hands of a certified professional. Work-release programs and other alternatives to incarceration also could ease strains on the center. NO.

5. Public Libraries: $10.4 million. This is for three new libraries in the Reston, Tysons-Pimmit and Pohick areas and for renovation of the Central Library on Chain Bridge Road. It is a phase of the long-range capital improvement program for the county system. YES.