how to say no to a friend who has already done us a favour

[Ash21]

iam a university student living with my family.when i have final exams my mom and sis drive me to college and pick me up too.other days i use the college bus.
Two of my not very close friends who live in the neighbourhood tag along ,and i find it impossible to say no to them ,as one of them had helped me in lab work.
but i find it irrtating to have them going with me ,because i need some space.but they have behaved very friendly from the time they realised they could use me.that is why one of them helped me with the lab work.earlier they wouldnt even talk to me maybe just a hi sometimes.i have taken them a couple of times but i really want to be alone ie(only someone from my family for support) to be with me.dont tell me to take the bus-esp during exams,i find it tiring.how do i say no to them without spoiling our relationship or should i give an excuse that i hav obliged to pick someone else/(an old friend) please reply.

[888sally888]

I would be honest and say that you find this time alone with your family very important to get you in the right calm frame of mind when you have exams. Just say you get stressed and need some really peaceful time alone.

[WendyS]

I agree. Tell them that you're finding it difficult to keep on top of your universithy work and that you really do need a little space at exam times when the company of others makes you feel particularly stressed. Be honest and say that at times like this, you don't enjoy the company of others because of the emotional demands it makes on you. Could you find some excuse to deviate your journey times so that giving them a lift is not viable.

[joko]

why not just put music on some headphones to block them out?

sit in the front and tell them you need calm and space and to not talk to you at all.

i understand your problem, but they have spent time and effort helping you to pass the exam, and away from their own studies - you are merely allowing them car space, to save them time and money.

i don't think its much too ask.

[lizzydrippin]

Are we talking about a long journey or what?

[gothicdejavu]

Have a cardboard box? One of those boxes the TV or washing machine comes in? Is it empty? You can ride in the front, sister in the back with the huge box taking all of the rest of the space, and your moms driving. The back doors are locked to avoid inadvertent inspections, (cos the box is heavy and might crash on the door which might swing open... I stress on an "empty" box cos after you've passed them friends, your sister (or you, but you'll have to turn around and stuff which could be uncomfortable) can fold it up and put it in the leg room.
You could say your moms agreed to keep transporting some raw cooking material to a friends bakery everyday...
I don't know... such people (your friendly friendS) are hard to handle..
Alternatively, you could just treat them to a nice dinner or something, make it a big thing to show your "ultimate" thank you... and make it look like it's a "give back" for all their help and that now you guys are even.
(the second plan will cost more than the first)