With the immense growth in the Washington region, particularly in the outlying suburbs, houses are being built far faster than schools. Many counties predict school populations will peak in the next decade, so they are reluctant to construct expensive school buildings and instead seek temporary solutions. Thousands of area students spend most of their day in trailers--and this year the number will grow again.

Critics complain that the act of having children trek to and from the main school building means learning time lost, colds caught in the rain and doors left unlocked and vulnerable to security threats. Then again, it's pretty peaceful in a trailer--no racket seeping in from the noisy science experiment in the next room, the space immediately warmed or cooled at the twitch of a thermostat--and trailers are often as big or bigger than regular classrooms.

Like it or not, portable classrooms are a reality, now and in the near future. Below, the number of classroom trailers to be used in each local jurisdiction this year.

ALEXANDRIA:

Elementary: 10

Total: 10

ARLINGTON COUNTY

Elementary: 104

Middle: 9

High: 2

Others: 12

Total: 127

CALVERT COUNTY

Elementary: 11

Middle: 7

High: 15

Other: 1

Total: 34

CHARLES COUNTY

Elementary: 63

Middle: 10

High: 36

Other: 1

Total: 110

FAIRFAX COUNTY

Elementary: 442

Middle: 108

High: 112

Total: 662

FALLS CHURCH:

Elementary: 2

Total: 2

FAUQUIER COUNTY:

Elementary: 6

Middle: 28

High: 2

Total: 36

HOWARD COUNTY

Elementary: 28

Middle: 6

High: 0

Total: 34

LOUDOUN COUNTY:

Elementary: 3

Middle: 2

High: 17

Total: 22

MANASSAS

Elementary: 16

Total: 16

MANASSAS PARK

Elementary: 15

Total: 15

MONTGOMERY COUNTY

Elementary: 148

Middle: 61

High: 53

Others: 24

Total: 286

PRINCE GEORGE'S COUNTY

Elementary: 268

Middle: 44

High: 102

Special centers: 14

Total: 428

PRINCE WILLIAM COUNTY

Elementary: 111

Middle: 19

High: 25

Others: 8

Total: 163

ST. MARY'S COUNTY:

Elementary: 27

Middle: 4

High: 13

Others: 27

Total: 71

STAFFORD COUNTY:

no trailers.

* Others includes alternative programs and schools and learning centers.