public string GetTripsOnLine(DateTime startDate, DateTime endDate, List<LatLong> linePoints)
        {
            using (TaxiDataEntities context = new TaxiDataEntities())
            {
                //build the line from the points given
                SqlGeography sqlLine = CreateLineFromPoints(linePoints);

                //kick off the stored procedure
                List<QueryDto> returnVal = context.LineWithVolume(startDate, endDate, sqlLine.ToString())
                                    .Select(x => new QueryDto
                                    {
                                        Pickup = new LatLong
                                        {
                                            Latitude = (double)x.pickup_latitude,
                                            Longitude = (double)x.pickup_longitude
                                        },
                                        Dropoff = new LatLong
                                        {
                                            Latitude = (double)x.dropoff_latitude,
                                            Longitude = (double)x.dropoff_longitude
                                        },
                                        FareTotal = x.total_amount,
                                        TravelTime = x.trip_time_in_secs,
                                        NumOfPassenger = x.passenger_count,
                                        TripDistance = x.trip_distance
                                    }).ToList();

                return JsonConvert.SerializeObject(returnVal);
            }
        }