$travel_details should be like this
$travel_details['Singleroute']=array(
'userprofile_id'=>$upid,
'day'=>$data['day'],
'dayNumeric'=>$daynum,
'morning_route'=>$morning_route,
'morning_time'=>$morning_time,
'evening_route'=>$evening_route,
'evening_time'=>$evening_time,
'traveller' =>$traveller
);
you need to specify the model in fields array. NOw run your query
$this->Singleroute->updateAll($travel_details,array('Singleroute.userprofile_id'=>$upid,'Singleroute.daynumeric'=>$daynum,
'Singleroute.day'=>$data['day']));
Read more for saving data here http://book.cakephp.org/1.3/en/The-Manual/Developing-with-CakePHP/Models.html#saving-your-data