00535nam a2200157 a 450000500170000000800410001703500150005804100070007305000200008010000210010024500720012126000750019330000080026844000810027665000200035720260817161201.0                                          a.b100212920 aEn  aTE7 T72 no. 431  aKember-Smith, J. 0a50-point census operators guide :ba supplement to RRL report no. 9  aCrowthorne, Berkshire :bTransport and Road Research Laboratory,c1978  a6 p 0aTransport and Road Research Laboratory. TRRL supplementary report ;vno. 431 0aTraffic surveys