Below are the toll free numbers for the taxi services available in Lausanne. Beware that taxis in Switzerland are expensive!

Taxi Services Sàrl

0800 810 810
Taxiphone 0800 801 802
Allô Taxis! 0800 870 872
CDI-CDS Call Dispatch System S.A. 0800 818 800
ABC Taxis Lausanne 0800 220 250

 The first question: is it taxis in Switzerland are really expensive? 

The answer depends on what taxi are you seeking for, so if you call a taxi from a large society with tall free numbers as mentioned before, sure you will have to pay high prices accordingly. But if you seek for economic prices you should call taxi drivers who are running a sole proprietorship taxi services such as:

 Taxii CH 077 983 85 86
 Taxi du Signal 076 426 69 25

In terms of renting a car, you can find many car rental agencies at the CFF train station on Avenue de la Gare, including Aloc-cars, Avis, and Europcar.  You can get 20% off bookings with Europcar if you book your rental through a link from the official Lausanne tourism board site,   Hertz has a location near Place du Tunnel, while Budget has an office at Chemin de Mornex. 

It is important to observe the speed limits (speed cameras are frequent and fines very expensive).  In town, the limits range from 30 (in designated zones) to 50 km per hour (about 20-30 miles per hour) outside town generally 80km/h, 120 km per hour (about 75 miles per hour) on the motorway/highway.  Note that you MUST have a motorway sticker to use the motorways (this is usually included with your car rental)

When parking your car, you should also be aware of the different parking zones (white, blue and metered).  Unmetered white zones are the best since it means that you can have unlimited parking, however they have now almost completely disappeared from the city centre.