The driver charged with hitting two children with a pickup truck pleaded not guilty yesterday and was ordered held on $1,000 bond when he was arraigned in Superior Court on a series of traffic charges.

Another hearing is to be held tomorrow in the case of Thomas Davis, 47, an employee of the D.C. Water and Sewer Authority. He was charged with leaving the scene and other misdemeanors after allegedly striking the two children in their stroller Thursday at Georgia and New Hampshire avenues NW.

The two boys, Jossan Zavala, 23 months, and Miguel Zavala, 9 months, were at Children's Hospital. The older boy remained in critical condition; the younger boy's condition was upgraded to fair.

Peter LaValle, a spokesman for the D.C. Corporation Counsel's office, which is prosecuting, said the maximum penalties for the offenses with which Davis is charged would amount to about two years in jail and $3,100 in fines.

However, a spokesman for the U.S. attorney's office, which prosecutes more serious offenses in Washington, said additional charges could be brought if it is determined that the children were struck as a result of "gross negligence."

Police said Thursday that the driver of the truck had apparently run a red light and left the scene. They said other motorists followed the vehicle and boxed it in.

Charges that have been filed against Davis include two counts of leaving the scene after a personal injury collision, failing to yield the right of way to a pedestrian, reckless driving and driving under the influence.

Assistant Corporation Counsel Kristen Nelson, who represented the city yesterday, said tests showed that there was no trace of alcohol in Davis's blood. She also told Judge Rhonda Winston that Davis said that he did not use drugs and that he has used marijuana.

Mike Davis, Thomas Davis's brother, said his brother is a diabetic who needs to take insulin twice a day and "has episodes in which he doesn't exactly know what he is doing."

Mike Davis expressed sorrow over the children's injuries but said he was disappointed that his brother was held. He said that his brother is no flight risk and that in holding him despite his condition, "they are playing politics with my brother's life."

In an interview, D.C. Council member Adrian M. Fenty (D-Ward 4), in whose ward the incident occurred, said residents were particularly concerned about the vehicle leaving the scene. "Fleeing should be seen as a very serious thing."

Thomas Davis, a D.C. Water and Sewer Authority driver, faces a maximum of about two years in jail and $3,100 in fines.