def _get_abs_pos(edge, rel_pos, edgestarts):
    """Compute the absolute positions from edges and relative positions.

    This is the variable we will ultimately use to plot individual vehicles.

    Parameters
    ----------
    edge : list of str
        list of edges at every time step
    rel_pos : list of float
        list of relative positions at every time step
    edgestarts : dict
        the absolute starting position of every edge

    Returns
    -------
    list of float
        the absolute positive for every sample
    """
    ret = []
    for edge_i, pos_i in zip(edge, rel_pos):
        ret.append(pos_i + edgestarts[edge_i])
    return ret