As previously mentioned, the CAL3QHCR model uses a full year of hourly meteorological data.  Use of representative meteorological data that has been collected on-site is preferred; however, if  on-site data is not available, National Weather Service (NWS) 110  data, representative of the area  being modeled, is acceptable. If NWS data is used, the model must be run for five consecutive  meteorological years. 111  Vehicular emission rates are estimated for queuing and idling vehicles using the EPA -approved  models: MOVES and California’s EMFAC. Emission rates for each idling and queuing link are  input into the CAL3QHC/R model as gram per vehicle -mile and gram per vehicle -hour,  respectively. Refer back to  Section E.2.4  ( Estimate On-Road Vehicle Emissions ) for the steps on  how to generate emission factors with MOVES and California’s EMFAC models.  Once the project-level emissions and dispersion modeling analysis is complete and pollutant  concentrations associated with the project have been computed, representative background  concentrations should be added to the predicted worst-case project-level concentration (for both  CO and PM). Background concentrations are typically obtained from a background monitoring  site not affected by the intersection (s) of interest. EPA’s AirData provides b ackground  monitoring data at different monitoring locations collected across the U. S. for the seven criteria  pollutants. 112  The evaluation and selection of monitoring data for use in a particular analysis must follow the  process defined in each area’s interagency consultation procedures. Background moni tored data  should also be adjusted for future-year conditions. Methods used to compute future background  concentrations for CO and PM hot-spot analyses are detailed in EPA’s  Guideline for Modeling  Carbon Monoxide from Roadway Intersection , and EPA’s  Transportation Conformity Guidance  for Quantitative Hot-spot Analyses in PM$_{2.5 }$and PM$_{10 }$Nonattainment and Maintenance Areas ,  respectively, mentioned above.  110 National Oceanic and Atmospheric Administration (NOAA), National Weather Service (NWS) at  http://www.weather.gov/.  111 EPA,  Addendum to The User's Guide to CAL3QHC Version 2.0 (CAL3QHC User's Guide)  by Peter A. Eckhoff  and Thomas N. Braverman, September 1995, http://www.epa.gov/scram001/userg/regmod/cal3qhcrug.pdf.  112 EPA’s AirData can be accessed from the following website: http://www.epa.gov/airdata/ad_rep_mon.html.  101$_{ }$ APPENDIX E$_{ }$ E.2.6.4 Vehicular Emission Rates  E.2.7  Estimate Background Data 