\begin{table}
\begin{center}
\caption{Wall clock times on different systems and with different
degrees of parallelization for the Los Angeles domain}
\vspace*{0.2in}
\begin{tabular}{|c|c|c|c|}
\hline
System & Basic & //LU & //LU + LB \\
\hline
Sequential AXP 400 & 3000 & - & - \\
Sequential AXP 500 & 2640 & - & - \\
\hline
PSC 5 AXP 400 & - & 959 & - \\
PSC 5 AXP 500 & 868 & 863 & 772 \\
PSC 10 AXP$^*$ & 604 & 576 & 505 \\
\hline
CMU 5 AXP 400 & - & 1037 & - \\
CMU 10 AXP 400 & - & 902 & 795 \\
\hline
Cray C90 1 proc & 2000 & - & - \\
Cray C90 5 proc & 680 & - & - \\
\hline
\end{tabular}
\end{center}
\end{table}

\begin{table}
\begin{center}
\caption{Wall clock times on different systems with highest
degree of parallelization for the Northeast domain}
\vspace*{0.2in}
\begin{tabular}{|c|c|c|}
\hline
System & Basic & //LU + LB \\
\hline
Sequential AXP 500 & 16200 & - \\
\hline
PSC 5 AXP 500 & - & 4360 \\
PSC 10 AXP$^*$ & - & 2719 \\
\hline
\end{tabular}
\end{center}
\end{table}