Context :

Aims : To examine the idea that dynamical parameters can be estimated by identifying locations in the solar neighbourhood where velocity distributions recovered from test particle simulations , match the observed local distribution .
Here , the dynamical influence of both the Galactic bar and the outer spiral pattern are taken into account .

Methods : The Milky Way disc is stirred by analytical potentials that are chosen to represent the two perturbations , the ratio of pattern speeds of which is explored , rather than held constant .
The velocity structure of the final configuration is presented as heliocentric velocity distributions at different locations .
These model velocity distributions are compared to the observed distribution in terms of a goodness-of-fit parameter that has been formulated here .
We monitor the spatial distribution of the maximal value of this goodness-of-fit parameter , for a given simulation , in order to constrain the solar position from this model .
Efficiency of a model is based on a study of this distribution as well as on other independent dynamical considerations .

Results : We reject the bar only and spiral only models and arrive at the following bar parameters from the bar+spiral simulations : bar pattern speed of 57.4 ^ { +2.8 } _ { -3.3 } Â km s ^ { -1 } kpc ^ { -1 } and a bar angle in [ 0 ^ { \circ } , 30 ^ { \circ } ] , where the error bands are \pm 1- \sigma .
However , extracting information in this way is no longer viable when the dynamical influence of the spiral pattern does not succumb to that of the bar ; an explanation for this is offered .
Orbital analysis indicates that even though the basic bimodality in the local velocity distribution can be attributed to scattering off the Outer Lindblad Resonance of the bar , it is the interaction of irregular orbits and orbits of other resonant families , that is responsible for the other moving groups ; it is realised that such interaction increases with the warmth of the background disk .

Conclusions :