Mobile Ad Hoc Networks (MANET) performance is affected by a number of factors, eg. speed, node density. In this paper we will focus on the effect of constrained mobility on the performance of the MANET protocol. Experiments were carried out to measure the performance of MANET protocols in two mobility patterns: random waypoint and Metropolitan Grid(M-Grid). The latter reflects the mobility pattern that would be encountered in inter-vehicle communication system. Our results show that MANET performance in the M-Grid mobility pattern is reduced considerable as compared to random waypoint. A parameter called coverage density index was proposed to normalize mobility patterns coverage and thus its connectivity. The probability of connectivity and route length provides an indication of the performance of MANET protocols given the mobility pattern.