I have problem with tableView:didSelectRowAtIndexPath:.
 (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    /*if (!self.detailViewController) {
        self.detailViewController = [[DetailViewController alloc] initWithNibName:@"DetailViewController" bundle:nil];
    }
    NSObject *object = [_objects objectAtIndex:indexPath.row];
    self.detailViewController.detailItem = object;
    [self.navigationController pushViewController:self.detailViewController animated:YES];*/
if (!self.travelViewController) {
    self.travelViewController = [[TravelViewController alloc] initWithNibName:@"TravelViewController" bundle:nil];
}
[self.navigationController pushViewController:self.travelViewController animated:YES];
}
pushViewController use in UIViewController but travelViewController inherits from UITableViewController.