It has been years since José Horlandy, executive president of Valledupar's chamber of commerce, has ventured further by land than the small airport on the city's edge. The roads connecting Valledupar, the capital of Cesar province, with the Caribbean coast or with distant Bogotá are notorious for kidnappings and hold-ups by leftwing rebels and criminals.
Of more than 1,700 people kidnapped in Colombia this year, nearly one in ten has been seized in Cesar. Last year Consuelo Araujo, the minister of culture and a popular local figure, was kidnapped near Valledupar by the Revolutionary Armed Forces of Colombia (Farc) and killed.
Cesar is one of the most lawless zones of a lawless country - which is why President Alvaro Uribe, who took office this month vowing to improve security as his top priority, chose the region to launch one of the most important aspects of his law and order policy.
Over the past month almost 800 of the province's people have agreed to become police informants, under conditions of strict anonymity. They and members of similar pilot schemes in adjoining provinces alert authorities to any potential dangers on the region's roads. In return they receive rewards, amounting to several times the monthly minimum wage in some cases.
A week after unveiling the policy, Mr Uribe returned to Valledupar to hear encouraging results: a reported 43 per cent increase in traffic on Cesar's main highways.
This has not yet tempted Mr Horlandy to venture out. "We need to see more results", he says. "But people are beginning to have trust."
Police captain Angel Rojas, who says he is one of only two people to know the new informants' identities, wants to get at least 4,000 such collaborators in the province, covering highways and also rural areas where rebels might pass. "We want to awaken public spiritedness," he says.
One informant says he is "proud to be giving something to the country". The idea is to widen the scheme across the nation.
Colombians have not always seen the state as an ally. For Mr Uribe, though, engaging citizens in the fight against the guerrillas is fundamental. State forces are stretched too thinly and around 180 of Colombia's 1,100 municipalities have no police or army presence.
By promoting a network of paid informants the government hopes to improve security quickly and cheaply. There are also plans to recruit 15,000 peasants by March as part-time police and soldiers, as a way of boosting troop numbers.
Mr Uribe is also reinforcing a message to allies such as the US that Colombian society is willing to shoulder more of the burden of improving security and not rely on outside aid. Mr Uribe has already decreed a one-off tax on the wealthiest to pay for extra military spending.
However, reliance on civilians to help security forces is controversial. One expert in international humanitarian law says civilians who carry out intelligence work risk crossing a legal line when they could become legitimate targets for the guerrillas. Any part-time soldiers recruited will live at home, so there are concerns that their families could become targets.
Captain Rojas admits that some informants could be guerrilla or paramilitary plants setting up traps - so police intelligence officers corroborate any tip-offs, slowing response times.
And though police vow that informants' identities will be protected, leaks are a concern. There is already thought to be widespread guerrilla and paramilitary infiltration of most state authorities and many businesses such as banks, to spot potential extortion or kidnap targets. "The networks are going to need very prudent management," says Mr Horlandy. "Innocent people could get sacrificed."
Business leaders remain optimistic that one of Mr Uribe's key aims - restoring confidence - can be achieved. But they warn that bringing peace to the highways will only be a first step in solving Cesar's problems.
Farmers complain of huge debts that stifle any chance to invest. Agriculture has been decimated by foreign competition since 1990, and the area of land being cultivated in Cesar has fallen almost 60 per cent, halving agricultural employment.
Economic problems have exacerbated the violence, says Joaquín Tomás Ovalle, manager of Cesar's Association of Agricultural Products, by forcing jobless peasants to join the armed groups to support themselves. "Cesar cannot just be a laboratory for protecting the roads. We need irrigation, different crops," says Mr Ovalle, an Uribe supporter. "We could have a thousand tanks on the roads but if people are dying of hunger they will go on committing crimes."